NAME¶
perlapi - autogenerated documentation for the perl public API
DESCRIPTION¶
This file contains the documentation of the perl public API generated by
embed.pl, specifically a listing of functions, macros, flags, and
variables that may be used by extension writers. At the end is a list of
functions which have yet to be documented. The interfaces of those are subject
to change without notice. Anything not listed here is not part of the public
API, and should not be used by extension writers at all. For these reasons,
blindly using functions listed in proto.h is to be avoided when writing
extensions.
Note that all Perl API global variables must be referenced with the
"PL_" prefix. Again, those not listed here are not to be used by
extension writers, and can be changed or removed without notice; same with
macros. Some macros are provided for compatibility with the older, unadorned
names, but this support may be disabled in a future release.
Perl was originally written to handle US-ASCII only (that is characters whose
ordinal numbers are in the range 0 - 127). And documentation and comments may
still use the term ASCII, when sometimes in fact the entire range from 0 - 255
is meant.
Note that Perl can be compiled and run under EBCDIC (See perlebcdic) or ASCII.
Most of the documentation (and even comments in the code) ignore the EBCDIC
possibility. For almost all purposes the differences are transparent. As an
example, under EBCDIC, instead of UTF-8, UTF-EBCDIC is used to encode Unicode
strings, and so whenever this documentation refers to "utf8" (and
variants of that name, including in function names), it also (essentially
transparently) means "UTF-EBCDIC". But the ordinals of characters
differ between ASCII, EBCDIC, and the UTF- encodings, and a string encoded in
UTF-EBCDIC may occupy more bytes than in UTF-8.
The listing below is alphabetical, case insensitive.
"Gimme" Values¶
- GIMME
- A backward-compatible version of "GIMME_V" which can only return
"G_SCALAR" or "G_ARRAY"; in a void context, it returns
"G_SCALAR". Deprecated. Use "GIMME_V" instead.
U32 GIMME
- GIMME_V
- The XSUB-writer's equivalent to Perl's "wantarray". Returns
"G_VOID", "G_SCALAR" or "G_ARRAY" for void,
scalar or list context, respectively. See perlcall for a usage example.
U32 GIMME_V
- G_ARRAY
- Used to indicate list context. See "GIMME_V", "GIMME"
and perlcall.
- G_DISCARD
- Indicates that arguments returned from a callback should be discarded. See
perlcall.
- G_EVAL
- Used to force a Perl "eval" wrapper around a callback. See
perlcall.
- G_NOARGS
- Indicates that no arguments are being sent to a callback. See
perlcall.
- G_SCALAR
- Used to indicate scalar context. See "GIMME_V",
"GIMME", and perlcall.
- G_VOID
- Used to indicate void context. See "GIMME_V" and perlcall.
Array Manipulation Functions¶
- AvFILL
- Same as "av_top_index()". Deprecated, use
"av_top_index()" instead.
int AvFILL(AV* av)
- av_clear
- Clears an array, making it empty. Does not free the memory the av uses to
store its list of scalars. If any destructors are triggered as a result,
the av itself may be freed when this function returns.
Perl equivalent: "@myarray = ();".
void av_clear(AV *av)
- av_create_and_push
- NOTE: this function is experimental and may change or be removed without
notice.
Push an SV onto the end of the array, creating the array if necessary. A
small internal helper function to remove a commonly duplicated idiom.
void av_create_and_push(AV **const avp,
SV *const val)
- av_create_and_unshift_one
- NOTE: this function is experimental and may change or be removed without
notice.
Unshifts an SV onto the beginning of the array, creating the array if
necessary. A small internal helper function to remove a commonly
duplicated idiom.
SV** av_create_and_unshift_one(AV **const avp,
SV *const val)
- av_delete
- Deletes the element indexed by "key" from the array, makes the
element mortal, and returns it. If "flags" equals
"G_DISCARD", the element is freed and null is returned. Perl
equivalent: "my $elem = delete($myarray[$idx]);" for the
non-"G_DISCARD" version and a void-context
"delete($myarray[$idx]);" for the "G_DISCARD" version.
SV* av_delete(AV *av, SSize_t key, I32 flags)
- av_exists
- Returns true if the element indexed by "key" has been
initialized.
This relies on the fact that uninitialized array elements are set to NULL.
Perl equivalent: "exists($myarray[$key])".
bool av_exists(AV *av, SSize_t key)
- av_extend
- Pre-extend an array. The "key" is the index to which the array
should be extended.
void av_extend(AV *av, SSize_t key)
- av_fetch
- Returns the SV at the specified index in the array. The "key" is
the index. If lval is true, you are guaranteed to get a real SV back (in
case it wasn't real before), which you can then modify. Check that the
return value is non-null before dereferencing it to a "SV*".
See "Understanding the Magic of Tied Hashes and Arrays" in
perlguts for more information on how to use this function on tied arrays.
The rough perl equivalent is $myarray[$idx].
SV** av_fetch(AV *av, SSize_t key, I32 lval)
- av_fill
- Set the highest index in the array to the given number, equivalent to
Perl's "$#array = $fill;".
The number of elements in the array will be "fill + 1" after
av_fill() returns. If the array was previously shorter, then the
additional elements appended are set to NULL. If the array was longer,
then the excess elements are freed. "av_fill(av, -1)" is the
same as "av_clear(av)".
void av_fill(AV *av, SSize_t fill)
- av_len
- Same as "av_top_index". Note that, unlike what the name implies,
it returns the highest index in the array, so to get the size of the array
you need to use "av_len(av) + 1". This is unlike
"sv_len", which returns what you would expect.
SSize_t av_len(AV *av)
- av_make
- Creates a new AV and populates it with a list of SVs. The SVs are copied
into the array, so they may be freed after the call to av_make. The new AV
will have a reference count of 1.
Perl equivalent: "my @new_array = ($scalar1, $scalar2,
$scalar3...);"
AV* av_make(SSize_t size, SV **strp)
- av_pop
- Removes one SV from the end of the array, reducing its size by one and
returning the SV (transferring control of one reference count) to the
caller. Returns &PL_sv_undef if the array is empty.
Perl equivalent: "pop(@myarray);"
SV* av_pop(AV *av)
- av_push
- Pushes an SV onto the end of the array. The array will grow automatically
to accommodate the addition. This takes ownership of one reference count.
Perl equivalent: "push @myarray, $elem;".
void av_push(AV *av, SV *val)
- av_shift
- Removes one SV from the start of the array, reducing its size by one and
returning the SV (transferring control of one reference count) to the
caller. Returns &PL_sv_undef if the array is empty.
Perl equivalent: "shift(@myarray);"
SV* av_shift(AV *av)
- av_store
- Stores an SV in an array. The array index is specified as "key".
The return value will be NULL if the operation failed or if the value did
not need to be actually stored within the array (as in the case of tied
arrays). Otherwise, it can be dereferenced to get the "SV*" that
was stored there (= "val")).
Note that the caller is responsible for suitably incrementing the reference
count of "val" before the call, and decrementing it if the
function returned NULL.
Approximate Perl equivalent: "$myarray[$key] = $val;".
See "Understanding the Magic of Tied Hashes and Arrays" in
perlguts for more information on how to use this function on tied arrays.
SV** av_store(AV *av, SSize_t key, SV *val)
- av_tindex
- Same as "av_top_index()".
int av_tindex(AV* av)
- av_top_index
- Returns the highest index in the array. The number of elements in the
array is "av_top_index(av) + 1". Returns -1 if the array is
empty.
The Perl equivalent for this is $#myarray.
(A slightly shorter form is "av_tindex".)
SSize_t av_top_index(AV *av)
- av_undef
- Undefines the array. Frees the memory used by the av to store its list of
scalars. If any destructors are triggered as a result, the av itself may
be freed.
void av_undef(AV *av)
- av_unshift
- Unshift the given number of "undef" values onto the beginning of
the array. The array will grow automatically to accommodate the addition.
You must then use "av_store" to assign values to these new
elements.
Perl equivalent: "unshift @myarray, ( (undef) x $n );"
void av_unshift(AV *av, SSize_t num)
- get_av
- Returns the AV of the specified Perl global or package array with the
given name (so it won't work on lexical variables). "flags" are
passed to "gv_fetchpv". If "GV_ADD" is set and the
Perl variable does not exist then it will be created. If "flags"
is zero and the variable does not exist then NULL is returned.
Perl equivalent: "@{"$name"}".
NOTE: the perl_ form of this function is deprecated.
AV* get_av(const char *name, I32 flags)
- newAV
- Creates a new AV. The reference count is set to 1.
Perl equivalent: "my @array;".
AV* newAV()
- sortsv
- Sort an array. Here is an example:
sortsv(AvARRAY(av), av_top_index(av)+1, Perl_sv_cmp_locale);
Currently this always uses mergesort. See sortsv_flags for a more flexible
routine.
void sortsv(SV** array, size_t num_elts,
SVCOMPARE_t cmp)
- sortsv_flags
- Sort an array, with various options.
void sortsv_flags(SV** array, size_t num_elts,
SVCOMPARE_t cmp, U32 flags)
Callback Functions¶
- call_argv
- Performs a callback to the specified named and package-scoped Perl
subroutine with "argv" (a NULL-terminated array of strings) as
arguments. See perlcall.
Approximate Perl equivalent:
"&{"$sub_name"}(@$argv)".
NOTE: the perl_ form of this function is deprecated.
I32 call_argv(const char* sub_name, I32 flags,
char** argv)
- call_method
- Performs a callback to the specified Perl method. The blessed object must
be on the stack. See perlcall.
NOTE: the perl_ form of this function is deprecated.
I32 call_method(const char* methname, I32 flags)
- call_pv
- Performs a callback to the specified Perl sub. See perlcall.
NOTE: the perl_ form of this function is deprecated.
I32 call_pv(const char* sub_name, I32 flags)
- call_sv
- Performs a callback to the Perl sub whose name is in the SV. See perlcall.
NOTE: the perl_ form of this function is deprecated.
I32 call_sv(SV* sv, VOL I32 flags)
- ENTER
- Opening bracket on a callback. See "LEAVE" and perlcall.
ENTER;
- eval_pv
- Tells Perl to "eval" the given string in scalar context and
return an SV* result.
NOTE: the perl_ form of this function is deprecated.
SV* eval_pv(const char* p, I32 croak_on_error)
- eval_sv
- Tells Perl to "eval" the string in the SV. It supports the same
flags as "call_sv", with the obvious exception of G_EVAL. See
perlcall.
NOTE: the perl_ form of this function is deprecated.
I32 eval_sv(SV* sv, I32 flags)
- FREETMPS
- Closing bracket for temporaries on a callback. See "SAVETMPS"
and perlcall.
FREETMPS;
- LEAVE
- Closing bracket on a callback. See "ENTER" and perlcall.
LEAVE;
- SAVETMPS
- Opening bracket for temporaries on a callback. See "FREETMPS"
and perlcall.
SAVETMPS;
Character case changing¶
- toFOLD
- Converts the specified character to foldcase. If the input is anything but
an ASCII uppercase character, that input character itself is returned.
Variant "toFOLD_A" is equivalent. (There is no equivalent
"to_FOLD_L1" for the full Latin1 range, as the full generality
of "toFOLD_uni" is needed there.)
U8 toFOLD(U8 ch)
- toFOLD_uni
- Converts the Unicode code point "cp" to its foldcase version,
and stores that in UTF-8 in "s", and its length in bytes in
"lenp". Note that the buffer pointed to by "s" needs
to be at least "UTF8_MAXBYTES_CASE+1" bytes since the foldcase
version may be longer than the original character.
The first code point of the foldcased version is returned (but note, as
explained just above, that there may be more.)
UV toFOLD_uni(UV cp, U8* s, STRLEN* lenp)
- toFOLD_utf8
- Converts the UTF-8 encoded character at "p" to its foldcase
version, and stores that in UTF-8 in "s", and its length in
bytes in "lenp". Note that the buffer pointed to by
"s" needs to be at least "UTF8_MAXBYTES_CASE+1" bytes
since the foldcase version may be longer than the original character.
The first code point of the foldcased version is returned (but note, as
explained just above, that there may be more.)
The input character at "p" is assumed to be well-formed.
UV toFOLD_utf8(U8* p, U8* s, STRLEN* lenp)
- toLOWER
- Converts the specified character to lowercase. If the input is anything
but an ASCII uppercase character, that input character itself is returned.
Variant "toLOWER_A" is equivalent.
U8 toLOWER(U8 ch)
- toLOWER_L1
- Converts the specified Latin1 character to lowercase. The results are
undefined if the input doesn't fit in a byte.
U8 toLOWER_L1(U8 ch)
- toLOWER_LC
- Converts the specified character to lowercase using the current locale's
rules, if possible; otherwise returns the input character itself.
U8 toLOWER_LC(U8 ch)
- toLOWER_uni
- Converts the Unicode code point "cp" to its lowercase version,
and stores that in UTF-8 in "s", and its length in bytes in
"lenp". Note that the buffer pointed to by "s" needs
to be at least "UTF8_MAXBYTES_CASE+1" bytes since the lowercase
version may be longer than the original character.
The first code point of the lowercased version is returned (but note, as
explained just above, that there may be more.)
UV toLOWER_uni(UV cp, U8* s, STRLEN* lenp)
- toLOWER_utf8
- Converts the UTF-8 encoded character at "p" to its lowercase
version, and stores that in UTF-8 in "s", and its length in
bytes in "lenp". Note that the buffer pointed to by
"s" needs to be at least "UTF8_MAXBYTES_CASE+1" bytes
since the lowercase version may be longer than the original character.
The first code point of the lowercased version is returned (but note, as
explained just above, that there may be more.)
The input character at "p" is assumed to be well-formed.
UV toLOWER_utf8(U8* p, U8* s, STRLEN* lenp)
- toTITLE
- Converts the specified character to titlecase. If the input is anything
but an ASCII lowercase character, that input character itself is returned.
Variant "toTITLE_A" is equivalent. (There is no
"toTITLE_L1" for the full Latin1 range, as the full generality
of "toTITLE_uni" is needed there. Titlecase is not a concept
used in locale handling, so there is no functionality for that.)
U8 toTITLE(U8 ch)
- toTITLE_uni
- Converts the Unicode code point "cp" to its titlecase version,
and stores that in UTF-8 in "s", and its length in bytes in
"lenp". Note that the buffer pointed to by "s" needs
to be at least "UTF8_MAXBYTES_CASE+1" bytes since the titlecase
version may be longer than the original character.
The first code point of the titlecased version is returned (but note, as
explained just above, that there may be more.)
UV toTITLE_uni(UV cp, U8* s, STRLEN* lenp)
- toTITLE_utf8
- Converts the UTF-8 encoded character at "p" to its titlecase
version, and stores that in UTF-8 in "s", and its length in
bytes in "lenp". Note that the buffer pointed to by
"s" needs to be at least "UTF8_MAXBYTES_CASE+1" bytes
since the titlecase version may be longer than the original character.
The first code point of the titlecased version is returned (but note, as
explained just above, that there may be more.)
The input character at "p" is assumed to be well-formed.
UV toTITLE_utf8(U8* p, U8* s, STRLEN* lenp)
- toUPPER
- Converts the specified character to uppercase. If the input is anything
but an ASCII lowercase character, that input character itself is returned.
Variant "toUPPER_A" is equivalent.
U8 toUPPER(U8 ch)
- toUPPER_uni
- Converts the Unicode code point "cp" to its uppercase version,
and stores that in UTF-8 in "s", and its length in bytes in
"lenp". Note that the buffer pointed to by "s" needs
to be at least "UTF8_MAXBYTES_CASE+1" bytes since the uppercase
version may be longer than the original character.
The first code point of the uppercased version is returned (but note, as
explained just above, that there may be more.)
UV toUPPER_uni(UV cp, U8* s, STRLEN* lenp)
- toUPPER_utf8
- Converts the UTF-8 encoded character at "p" to its uppercase
version, and stores that in UTF-8 in "s", and its length in
bytes in "lenp". Note that the buffer pointed to by
"s" needs to be at least "UTF8_MAXBYTES_CASE+1" bytes
since the uppercase version may be longer than the original character.
The first code point of the uppercased version is returned (but note, as
explained just above, that there may be more.)
The input character at "p" is assumed to be well-formed.
UV toUPPER_utf8(U8* p, U8* s, STRLEN* lenp)
Character classes¶
This section is about functions (really macros) that classify characters into
types, such as punctuation versus alphabetic, etc. Most of these are analogous
to regular expression character classes. (See "POSIX Character
Classes" in perlrecharclass.) There are several variants for each class.
(Not all macros have all variants; each item below lists the ones valid for
it.) None are affected by "use bytes", and only the ones with
"LC" in the name are affected by the current locale.
The base function, e.g., "isALPHA()", takes an octet (either a
"char" or a "U8") as input and returns a boolean as to
whether or not the character represented by that octet is (or on non-ASCII
platforms, corresponds to) an ASCII character in the named class based on
platform, Unicode, and Perl rules. If the input is a number that doesn't fit
in an octet, FALSE is returned.
Variant "isFOO_A" (e.g., "isALPHA_A()") is identical to the
base function with no suffix "_A".
Variant "isFOO_L1" imposes the Latin-1 (or EBCDIC equivlalent)
character set onto the platform. That is, the code points that are ASCII are
unaffected, since ASCII is a subset of Latin-1. But the non-ASCII code points
are treated as if they are Latin-1 characters. For example,
"isWORDCHAR_L1()" will return true when called with the code point
0xDF, which is a word character in both ASCII and EBCDIC (though it represents
different characters in each).
Variant "isFOO_uni" is like the "isFOO_L1" variant, but
accepts any UV code point as input. If the code point is larger than 255,
Unicode rules are used to determine if it is in the character class. For
example, "isWORDCHAR_uni(0x100)" returns TRUE, since 0x100 is LATIN
CAPITAL LETTER A WITH MACRON in Unicode, and is a word character.
Variant "isFOO_utf8" is like "isFOO_uni", but the input is a
pointer to a (known to be well-formed) UTF-8 encoded string ("U8*"
or "char*"). The classification of just the first (possibly
multi-byte) character in the string is tested.
Variant "isFOO_LC" is like the "isFOO_A" and
"isFOO_L1" variants, but the result is based on the current locale,
which is what "LC" in the name stands for. If Perl can determine
that the current locale is a UTF-8 locale, it uses the published Unicode
rules; otherwise, it uses the C library function that gives the named
classification. For example, "isDIGIT_LC()" when not in a UTF-8
locale returns the result of calling "isdigit()". FALSE is always
returned if the input won't fit into an octet.
Variant "isFOO_LC_uvchr" is like "isFOO_LC", but is defined
on any UV. It returns the same as "isFOO_LC" for input code points
less than 256, and returns the hard-coded, not-affected-by-locale, Unicode
results for larger ones.
Variant "isFOO_LC_utf8" is like "isFOO_LC_uvchr", but the
input is a pointer to a (known to be well-formed) UTF-8 encoded string
("U8*" or "char*"). The classification of just the first
(possibly multi-byte) character in the string is tested.
- isALPHA
- Returns a boolean indicating whether the specified character is an
alphabetic character, analogous to "m/[[:alpha:]]/". See the top
of this section for an explanation of variants "isALPHA_A",
"isALPHA_L1", "isALPHA_uni", "isALPHA_utf8",
"isALPHA_LC", "isALPHA_LC_uvchr", and
"isALPHA_LC_utf8".
bool isALPHA(char ch)
- isALPHANUMERIC
- Returns a boolean indicating whether the specified character is a either
an alphabetic character or decimal digit, analogous to
"m/[[:alnum:]]/". See the top of this section for an explanation
of variants "isALPHANUMERIC_A", "isALPHANUMERIC_L1",
"isALPHANUMERIC_uni", "isALPHANUMERIC_utf8",
"isALPHANUMERIC_LC", "isALPHANUMERIC_LC_uvchr", and
"isALPHANUMERIC_LC_utf8".
bool isALPHANUMERIC(char ch)
- isASCII
- Returns a boolean indicating whether the specified character is one of the
128 characters in the ASCII character set, analogous to
"m/[[:ascii:]]/". On non-ASCII platforms, it returns TRUE iff
this character corresponds to an ASCII character. Variants
"isASCII_A()" and "isASCII_L1()" are identical to
"isASCII()". See the top of this section for an explanation of
variants "isASCII_uni", "isASCII_utf8",
"isASCII_LC", "isASCII_LC_uvchr", and
"isASCII_LC_utf8". Note, however, that some platforms do not
have the C library routine "isascii()". In these cases, the
variants whose names contain "LC" are the same as the
corresponding ones without.
Also note, that because all ASCII characters are UTF-8 invariant (meaning
they have the exact same representation (always a single byte) whether
encoded in UTF-8 or not), "isASCII" will give the correct
results when called with any byte in any string encoded or not in UTF-8.
And similarly "isASCII_utf8" will work properly on any string
encoded or not in UTF-8.
bool isASCII(char ch)
- isBLANK
- Returns a boolean indicating whether the specified character is a
character considered to be a blank, analogous to
"m/[[:blank:]]/". See the top of this section for an explanation
of variants "isBLANK_A", "isBLANK_L1",
"isBLANK_uni", "isBLANK_utf8", "isBLANK_LC",
"isBLANK_LC_uvchr", and "isBLANK_LC_utf8". Note,
however, that some platforms do not have the C library routine
"isblank()". In these cases, the variants whose names contain
"LC" are the same as the corresponding ones without.
bool isBLANK(char ch)
- isCNTRL
- Returns a boolean indicating whether the specified character is a control
character, analogous to "m/[[:cntrl:]]/". See the top of this
section for an explanation of variants "isCNTRL_A",
"isCNTRL_L1", "isCNTRL_uni", "isCNTRL_utf8",
"isCNTRL_LC", "isCNTRL_LC_uvchr", and
"isCNTRL_LC_utf8" On EBCDIC platforms, you almost always want to
use the "isCNTRL_L1" variant.
bool isCNTRL(char ch)
- isDIGIT
- Returns a boolean indicating whether the specified character is a digit,
analogous to "m/[[:digit:]]/". Variants "isDIGIT_A"
and "isDIGIT_L1" are identical to "isDIGIT". See the
top of this section for an explanation of variants
"isDIGIT_uni", "isDIGIT_utf8", "isDIGIT_LC",
"isDIGIT_LC_uvchr", and "isDIGIT_LC_utf8".
bool isDIGIT(char ch)
- isGRAPH
- Returns a boolean indicating whether the specified character is a graphic
character, analogous to "m/[[:graph:]]/". See the top of this
section for an explanation of variants "isGRAPH_A",
"isGRAPH_L1", "isGRAPH_uni", "isGRAPH_utf8",
"isGRAPH_LC", "isGRAPH_LC_uvchr", and
"isGRAPH_LC_utf8".
bool isGRAPH(char ch)
- isIDCONT
- Returns a boolean indicating whether the specified character can be the
second or succeeding character of an identifier. This is very close to,
but not quite the same as the official Unicode property
"XID_Continue". The difference is that this returns true only if
the input character also matches "isWORDCHAR". See the top of
this section for an explanation of variants "isIDCONT_A",
"isIDCONT_L1", "isIDCONT_uni",
"isIDCONT_utf8", "isIDCONT_LC",
"isIDCONT_LC_uvchr", and "isIDCONT_LC_utf8".
bool isIDCONT(char ch)
- isIDFIRST
- Returns a boolean indicating whether the specified character can be the
first character of an identifier. This is very close to, but not quite the
same as the official Unicode property "XID_Start". The
difference is that this returns true only if the input character also
matches "isWORDCHAR". See the top of this section for an
explanation of variants "isIDFIRST_A", "isIDFIRST_L1",
"isIDFIRST_uni", "isIDFIRST_utf8",
"isIDFIRST_LC", "isIDFIRST_LC_uvchr", and
"isIDFIRST_LC_utf8".
bool isIDFIRST(char ch)
- isLOWER
- Returns a boolean indicating whether the specified character is a
lowercase character, analogous to "m/[[:lower:]]/". See the top
of this section for an explanation of variants "isLOWER_A",
"isLOWER_L1", "isLOWER_uni", "isLOWER_utf8",
"isLOWER_LC", "isLOWER_LC_uvchr", and
"isLOWER_LC_utf8".
bool isLOWER(char ch)
- isOCTAL
- Returns a boolean indicating whether the specified character is an octal
digit, [0-7]. The only two variants are "isOCTAL_A" and
"isOCTAL_L1"; each is identical to "isOCTAL".
bool isOCTAL(char ch)
- isPRINT
- Returns a boolean indicating whether the specified character is a
printable character, analogous to "m/[[:print:]]/". See the top
of this section for an explanation of variants "isPRINT_A",
"isPRINT_L1", "isPRINT_uni", "isPRINT_utf8",
"isPRINT_LC", "isPRINT_LC_uvchr", and
"isPRINT_LC_utf8".
bool isPRINT(char ch)
- isPSXSPC
- (short for Posix Space) Starting in 5.18, this is identical
(experimentally) in all its forms to the corresponding
"isSPACE()" macros. ("Experimentally" means that this
change may be backed out in 5.22 if field experience indicates that it was
unwise.) The locale forms of this macro are identical to their
corresponding "isSPACE()" forms in all Perl releases. In
releases prior to 5.18, the non-locale forms differ from their
"isSPACE()" forms only in that the "isSPACE()" forms
don't match a Vertical Tab, and the "isPSXSPC()" forms do.
Otherwise they are identical. Thus this macro is analogous to what
"m/[[:space:]]/" matches in a regular expression. See the top of
this section for an explanation of variants "isPSXSPC_A",
"isPSXSPC_L1", "isPSXSPC_uni",
"isPSXSPC_utf8", "isPSXSPC_LC",
"isPSXSPC_LC_uvchr", and "isPSXSPC_LC_utf8".
bool isPSXSPC(char ch)
- isPUNCT
- Returns a boolean indicating whether the specified character is a
punctuation character, analogous to "m/[[:punct:]]/". Note that
the definition of what is punctuation isn't as straightforward as one
might desire. See "POSIX Character Classes" in perlrecharclass
for details. See the top of this section for an explanation of variants
"isPUNCT_A", "isPUNCT_L1", "isPUNCT_uni",
"isPUNCT_utf8", "isPUNCT_LC",
"isPUNCT_LC_uvchr", and "isPUNCT_LC_utf8".
bool isPUNCT(char ch)
- isSPACE
- Returns a boolean indicating whether the specified character is a
whitespace character. This is analogous to what "m/\s/" matches
in a regular expression. Starting in Perl 5.18 (experimentally), this also
matches what "m/[[:space:]]/" does. ("Experimentally"
means that this change may be backed out in 5.22 if field experience
indicates that it was unwise.) Prior to 5.18, only the locale forms of
this macro (the ones with "LC" in their names) matched precisely
what "m/[[:space:]]/" does. In those releases, the only
difference, in the non-locale variants, was that "isSPACE()" did
not match a vertical tab. (See "isPSXSPC" for a macro that
matches a vertical tab in all releases.) See the top of this section for
an explanation of variants "isSPACE_A", "isSPACE_L1",
"isSPACE_uni", "isSPACE_utf8", "isSPACE_LC",
"isSPACE_LC_uvchr", and "isSPACE_LC_utf8".
bool isSPACE(char ch)
- isUPPER
- Returns a boolean indicating whether the specified character is an
uppercase character, analogous to "m/[[:upper:]]/". See the top
of this section for an explanation of variants "isUPPER_A",
"isUPPER_L1", "isUPPER_uni", "isUPPER_utf8",
"isUPPER_LC", "isUPPER_LC_uvchr", and
"isUPPER_LC_utf8".
bool isUPPER(char ch)
- isWORDCHAR
- Returns a boolean indicating whether the specified character is a
character that is a word character, analogous to what "m/\w/"
and "m/[[:word:]]/" match in a regular expression. A word
character is an alphabetic character, a decimal digit, a connecting
punctuation character (such as an underscore), or a "mark"
character that attaches to one of those (like some sort of accent).
"isALNUM()" is a synonym provided for backward compatibility,
even though a word character includes more than the standard C language
meaning of alphanumeric. See the top of this section for an explanation of
variants "isWORDCHAR_A", "isWORDCHAR_L1",
"isWORDCHAR_uni", "isWORDCHAR_utf8",
"isWORDCHAR_LC", "isWORDCHAR_LC_uvchr", and
"isWORDCHAR_LC_utf8".
bool isWORDCHAR(char ch)
- isXDIGIT
- Returns a boolean indicating whether the specified character is a
hexadecimal digit. In the ASCII range these are "[0-9A-Fa-f]".
Variants "isXDIGIT_A()" and "isXDIGIT_L1()" are
identical to "isXDIGIT()". See the top of this section for an
explanation of variants "isXDIGIT_uni",
"isXDIGIT_utf8", "isXDIGIT_LC",
"isXDIGIT_LC_uvchr", and "isXDIGIT_LC_utf8".
bool isXDIGIT(char ch)
Cloning an interpreter¶
- perl_clone
- Create and return a new interpreter by cloning the current one.
perl_clone takes these flags as parameters:
CLONEf_COPY_STACKS - is used to, well, copy the stacks also, without it we
only clone the data and zero the stacks, with it we copy the stacks and
the new perl interpreter is ready to run at the exact same point as the
previous one. The pseudo-fork code uses COPY_STACKS while the
threads->create doesn't.
CLONEf_KEEP_PTR_TABLE - perl_clone keeps a ptr_table with the pointer of the
old variable as a key and the new variable as a value, this allows it to
check if something has been cloned and not clone it again but rather just
use the value and increase the refcount. If KEEP_PTR_TABLE is not set then
perl_clone will kill the ptr_table using the function
"ptr_table_free(PL_ptr_table); PL_ptr_table = NULL;", reason to
keep it around is if you want to dup some of your own variable who are
outside the graph perl scans, example of this code is in threads.xs
create.
CLONEf_CLONE_HOST - This is a win32 thing, it is ignored on unix, it tells
perls win32host code (which is c++) to clone itself, this is needed on
win32 if you want to run two threads at the same time, if you just want to
do some stuff in a separate perl interpreter and then throw it away and
return to the original one, you don't need to do anything.
PerlInterpreter* perl_clone(
PerlInterpreter *proto_perl,
UV flags
)
Compile-time scope hooks¶
- BhkDISABLE
- NOTE: this function is experimental and may change or be removed without
notice.
Temporarily disable an entry in this BHK structure, by clearing the
appropriate flag. which is a preprocessor token indicating which
entry to disable.
void BhkDISABLE(BHK *hk, which)
- BhkENABLE
- NOTE: this function is experimental and may change or be removed without
notice.
Re-enable an entry in this BHK structure, by setting the appropriate flag.
which is a preprocessor token indicating which entry to enable.
This will assert (under -DDEBUGGING) if the entry doesn't contain a valid
pointer.
void BhkENABLE(BHK *hk, which)
- BhkENTRY_set
- NOTE: this function is experimental and may change or be removed without
notice.
Set an entry in the BHK structure, and set the flags to indicate it is
valid. which is a preprocessing token indicating which entry to
set. The type of ptr depends on the entry.
void BhkENTRY_set(BHK *hk, which, void *ptr)
- blockhook_register
- NOTE: this function is experimental and may change or be removed without
notice.
Register a set of hooks to be called when the Perl lexical scope changes at
compile time. See "Compile-time scope hooks" in perlguts.
NOTE: this function must be explicitly called as Perl_blockhook_register
with an aTHX_ parameter.
void Perl_blockhook_register(pTHX_ BHK *hk)
COP Hint Hashes¶
- cophh_2hv
- NOTE: this function is experimental and may change or be removed without
notice.
Generates and returns a standard Perl hash representing the full set of
key/value pairs in the cop hints hash cophh. flags is
currently unused and must be zero.
HV * cophh_2hv(const COPHH *cophh, U32 flags)
- cophh_copy
- NOTE: this function is experimental and may change or be removed without
notice.
Make and return a complete copy of the cop hints hash cophh.
COPHH * cophh_copy(COPHH *cophh)
- cophh_delete_pv
- NOTE: this function is experimental and may change or be removed without
notice.
Like "cophh_delete_pvn", but takes a nul-terminated string instead
of a string/length pair.
COPHH * cophh_delete_pv(const COPHH *cophh,
const char *key, U32 hash,
U32 flags)
- cophh_delete_pvn
- NOTE: this function is experimental and may change or be removed without
notice.
Delete a key and its associated value from the cop hints hash cophh,
and returns the modified hash. The returned hash pointer is in general not
the same as the hash pointer that was passed in. The input hash is
consumed by the function, and the pointer to it must not be subsequently
used. Use "cophh_copy" if you need both hashes.
The key is specified by keypv and keylen. If flags has
the "COPHH_KEY_UTF8" bit set, the key octets are interpreted as
UTF-8, otherwise they are interpreted as Latin-1. hash is a
precomputed hash of the key string, or zero if it has not been
precomputed.
COPHH * cophh_delete_pvn(COPHH *cophh,
const char *keypv,
STRLEN keylen, U32 hash,
U32 flags)
- cophh_delete_pvs
- NOTE: this function is experimental and may change or be removed without
notice.
Like "cophh_delete_pvn", but takes a literal string instead of a
string/length pair, and no precomputed hash.
COPHH * cophh_delete_pvs(const COPHH *cophh,
const char *key, U32 flags)
- cophh_delete_sv
- NOTE: this function is experimental and may change or be removed without
notice.
Like "cophh_delete_pvn", but takes a Perl scalar instead of a
string/length pair.
COPHH * cophh_delete_sv(const COPHH *cophh, SV *key,
U32 hash, U32 flags)
- cophh_fetch_pv
- NOTE: this function is experimental and may change or be removed without
notice.
Like "cophh_fetch_pvn", but takes a nul-terminated string instead
of a string/length pair.
SV * cophh_fetch_pv(const COPHH *cophh,
const char *key, U32 hash,
U32 flags)
- cophh_fetch_pvn
- NOTE: this function is experimental and may change or be removed without
notice.
Look up the entry in the cop hints hash cophh with the key specified
by keypv and keylen. If flags has the
"COPHH_KEY_UTF8" bit set, the key octets are interpreted as
UTF-8, otherwise they are interpreted as Latin-1. hash is a
precomputed hash of the key string, or zero if it has not been
precomputed. Returns a mortal scalar copy of the value associated with the
key, or &PL_sv_placeholder if there is no value associated with the
key.
SV * cophh_fetch_pvn(const COPHH *cophh,
const char *keypv,
STRLEN keylen, U32 hash,
U32 flags)
- cophh_fetch_pvs
- NOTE: this function is experimental and may change or be removed without
notice.
Like "cophh_fetch_pvn", but takes a literal string instead of a
string/length pair, and no precomputed hash.
SV * cophh_fetch_pvs(const COPHH *cophh,
const char *key, U32 flags)
- cophh_fetch_sv
- NOTE: this function is experimental and may change or be removed without
notice.
Like "cophh_fetch_pvn", but takes a Perl scalar instead of a
string/length pair.
SV * cophh_fetch_sv(const COPHH *cophh, SV *key,
U32 hash, U32 flags)
- cophh_free
- NOTE: this function is experimental and may change or be removed without
notice.
Discard the cop hints hash cophh, freeing all resources associated
with it.
void cophh_free(COPHH *cophh)
- cophh_new_empty
- NOTE: this function is experimental and may change or be removed without
notice.
Generate and return a fresh cop hints hash containing no entries.
COPHH * cophh_new_empty()
- cophh_store_pv
- NOTE: this function is experimental and may change or be removed without
notice.
Like "cophh_store_pvn", but takes a nul-terminated string instead
of a string/length pair.
COPHH * cophh_store_pv(const COPHH *cophh,
const char *key, U32 hash,
SV *value, U32 flags)
- cophh_store_pvn
- NOTE: this function is experimental and may change or be removed without
notice.
Stores a value, associated with a key, in the cop hints hash cophh,
and returns the modified hash. The returned hash pointer is in general not
the same as the hash pointer that was passed in. The input hash is
consumed by the function, and the pointer to it must not be subsequently
used. Use "cophh_copy" if you need both hashes.
The key is specified by keypv and keylen. If flags has
the "COPHH_KEY_UTF8" bit set, the key octets are interpreted as
UTF-8, otherwise they are interpreted as Latin-1. hash is a
precomputed hash of the key string, or zero if it has not been
precomputed.
value is the scalar value to store for this key. value is
copied by this function, which thus does not take ownership of any
reference to it, and later changes to the scalar will not be reflected in
the value visible in the cop hints hash. Complex types of scalar will not
be stored with referential integrity, but will be coerced to strings.
COPHH * cophh_store_pvn(COPHH *cophh, const char *keypv,
STRLEN keylen, U32 hash,
SV *value, U32 flags)
- cophh_store_pvs
- NOTE: this function is experimental and may change or be removed without
notice.
Like "cophh_store_pvn", but takes a literal string instead of a
string/length pair, and no precomputed hash.
COPHH * cophh_store_pvs(const COPHH *cophh,
const char *key, SV *value,
U32 flags)
- cophh_store_sv
- NOTE: this function is experimental and may change or be removed without
notice.
Like "cophh_store_pvn", but takes a Perl scalar instead of a
string/length pair.
COPHH * cophh_store_sv(const COPHH *cophh, SV *key,
U32 hash, SV *value, U32 flags)
COP Hint Reading¶
- cop_hints_2hv
- Generates and returns a standard Perl hash representing the full set of
hint entries in the cop cop. flags is currently unused and
must be zero.
HV * cop_hints_2hv(const COP *cop, U32 flags)
- cop_hints_fetch_pv
- Like "cop_hints_fetch_pvn", but takes a nul-terminated string
instead of a string/length pair.
SV * cop_hints_fetch_pv(const COP *cop,
const char *key, U32 hash,
U32 flags)
- cop_hints_fetch_pvn
- Look up the hint entry in the cop cop with the key specified by
keypv and keylen. If flags has the
"COPHH_KEY_UTF8" bit set, the key octets are interpreted as
UTF-8, otherwise they are interpreted as Latin-1. hash is a
precomputed hash of the key string, or zero if it has not been
precomputed. Returns a mortal scalar copy of the value associated with the
key, or &PL_sv_placeholder if there is no value associated with the
key.
SV * cop_hints_fetch_pvn(const COP *cop,
const char *keypv,
STRLEN keylen, U32 hash,
U32 flags)
- cop_hints_fetch_pvs
- Like "cop_hints_fetch_pvn", but takes a literal string instead
of a string/length pair, and no precomputed hash.
SV * cop_hints_fetch_pvs(const COP *cop,
const char *key, U32 flags)
- cop_hints_fetch_sv
- Like "cop_hints_fetch_pvn", but takes a Perl scalar instead of a
string/length pair.
SV * cop_hints_fetch_sv(const COP *cop, SV *key,
U32 hash, U32 flags)
Custom Operators¶
- custom_op_register
- Register a custom op. See "Custom Operators" in perlguts.
NOTE: this function must be explicitly called as Perl_custom_op_register
with an aTHX_ parameter.
void Perl_custom_op_register(pTHX_
Perl_ppaddr_t ppaddr,
const XOP *xop)
- custom_op_xop
- Return the XOP structure for a given custom op. This macro should be
considered internal to OP_NAME and the other access macros: use them
instead. This macro does call a function. Prior to 5.19.6, this was
implemented as a function.
NOTE: this function must be explicitly called as Perl_custom_op_xop with an
aTHX_ parameter.
const XOP * Perl_custom_op_xop(pTHX_ const OP *o)
- XopDISABLE
- Temporarily disable a member of the XOP, by clearing the appropriate flag.
void XopDISABLE(XOP *xop, which)
- XopENABLE
- Reenable a member of the XOP which has been disabled.
void XopENABLE(XOP *xop, which)
- XopENTRY
- Return a member of the XOP structure. which is a cpp token
indicating which entry to return. If the member is not set this will
return a default value. The return type depends on which. This
macro evaluates its arguments more than once. If you are using
"Perl_custom_op_xop" to retreive a "XOP *" from a
"OP *", use the more efficient "XopENTRYCUSTOM"
instead.
XopENTRY(XOP *xop, which)
- XopENTRYCUSTOM
- Exactly like "XopENTRY(XopENTRY(Perl_custom_op_xop(aTHX_ o),
which)" but more efficient. The which parameter is identical
to "XopENTRY".
XopENTRYCUSTOM(const OP *o, which)
- XopENTRY_set
- Set a member of the XOP structure. which is a cpp token indicating
which entry to set. See "Custom Operators" in perlguts for
details about the available members and how they are used. This macro
evaluates its argument more than once.
void XopENTRY_set(XOP *xop, which, value)
- XopFLAGS
- Return the XOP's flags.
U32 XopFLAGS(XOP *xop)
CV Manipulation Functions¶
- CvSTASH
- Returns the stash of the CV. A stash is the symbol table hash, containing
the package-scoped variables in the package where the subroutine was
defined. For more information, see perlguts.
This also has a special use with XS AUTOLOAD subs. See "Autoloading
with XSUBs" in perlguts.
HV* CvSTASH(CV* cv)
- get_cv
- Uses "strlen" to get the length of "name", then calls
"get_cvn_flags".
NOTE: the perl_ form of this function is deprecated.
CV* get_cv(const char* name, I32 flags)
- get_cvn_flags
- Returns the CV of the specified Perl subroutine. "flags" are
passed to "gv_fetchpvn_flags". If "GV_ADD" is set and
the Perl subroutine does not exist then it will be declared (which has the
same effect as saying "sub name;"). If "GV_ADD" is not
set and the subroutine does not exist then NULL is returned.
NOTE: the perl_ form of this function is deprecated.
CV* get_cvn_flags(const char* name, STRLEN len,
I32 flags)
Debugging Utilities¶
- dump_all
- Dumps the entire optree of the current program starting at
"PL_main_root" to "STDERR". Also dumps the optrees for
all visible subroutines in "PL_defstash".
void dump_all()
- dump_packsubs
- Dumps the optrees for all visible subroutines in "stash".
void dump_packsubs(const HV* stash)
- op_dump
- Dumps the optree starting at OP "o" to "STDERR".
void op_dump(const OP *o)
- sv_dump
- Dumps the contents of an SV to the "STDERR" filehandle.
For an example of its output, see Devel::Peek.
void sv_dump(SV* sv)
Embedding Functions¶
- cv_clone
- Clone a CV, making a lexical closure. proto supplies the prototype
of the function: its code, pad structure, and other attributes. The
prototype is combined with a capture of outer lexicals to which the code
refers, which are taken from the currently-executing instance of the
immediately surrounding code.
CV * cv_clone(CV *proto)
- cv_undef
- Clear out all the active components of a CV. This can happen either by an
explicit "undef &foo", or by the reference count going to
zero. In the former case, we keep the CvOUTSIDE pointer, so that any
anonymous children can still follow the full lexical scope chain.
void cv_undef(CV* cv)
- find_rundefsv
- Find and return the variable that is named $_ in the lexical scope of the
currently-executing function. This may be a lexical $_, or will otherwise
be the global one.
SV * find_rundefsv()
- find_rundefsvoffset
- DEPRECATED! It is planned to remove this function from a future release of
Perl. Do not use it for new code; remove it from existing code.
Find the position of the lexical $_ in the pad of the currently-executing
function. Returns the offset in the current pad, or "NOT_IN_PAD"
if there is no lexical $_ in scope (in which case the global one should be
used instead). "find_rundefsv" is likely to be more convenient.
NOTE: the perl_ form of this function is deprecated.
PADOFFSET find_rundefsvoffset()
- load_module
- Loads the module whose name is pointed to by the string part of name. Note
that the actual module name, not its filename, should be given. Eg,
"Foo::Bar" instead of "Foo/Bar.pm". flags can be any
of PERL_LOADMOD_DENY, PERL_LOADMOD_NOIMPORT, or PERL_LOADMOD_IMPORT_OPS
(or 0 for no flags). ver, if specified and not NULL, provides version
semantics similar to "use Foo::Bar VERSION". The optional
trailing SV* arguments can be used to specify arguments to the module's
import() method, similar to "use Foo::Bar VERSION LIST".
They must be terminated with a final NULL pointer. Note that this list can
only be omitted when the PERL_LOADMOD_NOIMPORT flag has been used.
Otherwise at least a single NULL pointer to designate the default import
list is required.
The reference count for each specified "SV*" parameter is
decremented.
void load_module(U32 flags, SV* name, SV* ver, ...)
- nothreadhook
- Stub that provides thread hook for perl_destruct when there are no
threads.
int nothreadhook()
- pad_add_anon
- Allocates a place in the currently-compiling pad (via
"pad_alloc") for an anonymous function that is lexically scoped
inside the currently-compiling function. The function func is
linked into the pad, and its "CvOUTSIDE" link to the outer scope
is weakened to avoid a reference loop.
One reference count is stolen, so you may need to do
"SvREFCNT_inc(func)".
optype should be an opcode indicating the type of operation that the
pad entry is to support. This doesn't affect operational semantics, but is
used for debugging.
PADOFFSET pad_add_anon(CV *func, I32 optype)
- pad_add_name_pv
- Exactly like "pad_add_name_pvn", but takes a nul-terminated
string instead of a string/length pair.
PADOFFSET pad_add_name_pv(const char *name, U32 flags,
HV *typestash, HV *ourstash)
- pad_add_name_pvn
- Allocates a place in the currently-compiling pad for a named lexical
variable. Stores the name and other metadata in the name part of the pad,
and makes preparations to manage the variable's lexical scoping. Returns
the offset of the allocated pad slot.
namepv/namelen specify the variable's name, including leading
sigil. If typestash is non-null, the name is for a typed lexical,
and this identifies the type. If ourstash is non-null, it's a
lexical reference to a package variable, and this identifies the package.
The following flags can be OR'ed together:
padadd_OUR redundantly specifies if it's a package var
padadd_STATE variable will retain value persistently
padadd_NO_DUP_CHECK skip check for lexical shadowing
PADOFFSET pad_add_name_pvn(const char *namepv,
STRLEN namelen, U32 flags,
HV *typestash, HV *ourstash)
- pad_add_name_sv
- Exactly like "pad_add_name_pvn", but takes the name string in
the form of an SV instead of a string/length pair.
PADOFFSET pad_add_name_sv(SV *name, U32 flags,
HV *typestash, HV *ourstash)
- pad_alloc
- NOTE: this function is experimental and may change or be removed without
notice.
Allocates a place in the currently-compiling pad, returning the offset of
the allocated pad slot. No name is initially attached to the pad slot.
tmptype is a set of flags indicating the kind of pad entry
required, which will be set in the value SV for the allocated pad entry:
SVs_PADMY named lexical variable ("my", "our", "state")
SVs_PADTMP unnamed temporary store
SVf_READONLY constant shared between recursion levels
"SVf_READONLY" has been supported here only since perl 5.20. To
work with earlier versions as well, use
"SVf_READONLY|SVs_PADTMP". "SVf_READONLY" does not
cause the SV in the pad slot to be marked read-only, but simply tells
"pad_alloc" that it will be made read-only (by the
caller), or at least should be treated as such.
optype should be an opcode indicating the type of operation that the
pad entry is to support. This doesn't affect operational semantics, but is
used for debugging.
PADOFFSET pad_alloc(I32 optype, U32 tmptype)
- pad_compname_type
- Looks up the type of the lexical variable at position po in the
currently-compiling pad. If the variable is typed, the stash of the class
to which it is typed is returned. If not, "NULL" is returned.
HV * pad_compname_type(PADOFFSET po)
- pad_findmy_pv
- Exactly like "pad_findmy_pvn", but takes a nul-terminated string
instead of a string/length pair.
PADOFFSET pad_findmy_pv(const char *name, U32 flags)
- pad_findmy_pvn
- Given the name of a lexical variable, find its position in the
currently-compiling pad. namepv/namelen specify the
variable's name, including leading sigil. flags is reserved and
must be zero. If it is not in the current pad but appears in the pad of
any lexically enclosing scope, then a pseudo-entry for it is added in the
current pad. Returns the offset in the current pad, or
"NOT_IN_PAD" if no such lexical is in scope.
PADOFFSET pad_findmy_pvn(const char *namepv,
STRLEN namelen, U32 flags)
- pad_findmy_sv
- Exactly like "pad_findmy_pvn", but takes the name string in the
form of an SV instead of a string/length pair.
PADOFFSET pad_findmy_sv(SV *name, U32 flags)
- pad_setsv
- Set the value at offset po in the current (compiling or executing)
pad. Use the macro PAD_SETSV() rather than calling this function
directly.
void pad_setsv(PADOFFSET po, SV *sv)
- pad_sv
- Get the value at offset po in the current (compiling or executing)
pad. Use macro PAD_SV instead of calling this function directly.
SV * pad_sv(PADOFFSET po)
- pad_tidy
- NOTE: this function is experimental and may change or be removed without
notice.
Tidy up a pad at the end of compilation of the code to which it belongs.
Jobs performed here are: remove most stuff from the pads of anonsub
prototypes; give it a @_; mark temporaries as such. type indicates
the kind of subroutine:
padtidy_SUB ordinary subroutine
padtidy_SUBCLONE prototype for lexical closure
padtidy_FORMAT format
void pad_tidy(padtidy_type type)
- perl_alloc
- Allocates a new Perl interpreter. See perlembed.
PerlInterpreter* perl_alloc()
- perl_construct
- Initializes a new Perl interpreter. See perlembed.
void perl_construct(PerlInterpreter *my_perl)
- perl_destruct
- Shuts down a Perl interpreter. See perlembed.
int perl_destruct(PerlInterpreter *my_perl)
- perl_free
- Releases a Perl interpreter. See perlembed.
void perl_free(PerlInterpreter *my_perl)
- perl_parse
- Tells a Perl interpreter to parse a Perl script. See perlembed.
int perl_parse(PerlInterpreter *my_perl,
XSINIT_t xsinit, int argc,
char** argv, char** env)
- perl_run
- Tells a Perl interpreter to run. See perlembed.
int perl_run(PerlInterpreter *my_perl)
- require_pv
- Tells Perl to "require" the file named by the string argument.
It is analogous to the Perl code "eval "require
'$file'"". It's even implemented that way; consider using
load_module instead.
NOTE: the perl_ form of this function is deprecated.
void require_pv(const char* pv)
Functions in file dump.c¶
- pv_display
- Similar to
pv_escape(dsv,pv,cur,pvlim,PERL_PV_ESCAPE_QUOTE);
except that an additional "\0" will be appended to the string when
len > cur and pv[cur] is "\0".
Note that the final string may be up to 7 chars longer than pvlim.
char* pv_display(SV *dsv, const char *pv, STRLEN cur,
STRLEN len, STRLEN pvlim)
- pv_escape
- Escapes at most the first "count" chars of pv and puts the
results into dsv such that the size of the escaped string will not exceed
"max" chars and will not contain any incomplete escape
sequences.
If flags contains PERL_PV_ESCAPE_QUOTE then any double quotes in the string
will also be escaped.
Normally the SV will be cleared before the escaped string is prepared, but
when PERL_PV_ESCAPE_NOCLEAR is set this will not occur.
If PERL_PV_ESCAPE_UNI is set then the input string is treated as Unicode, if
PERL_PV_ESCAPE_UNI_DETECT is set then the input string is scanned using
"is_utf8_string()" to determine if it is Unicode.
If PERL_PV_ESCAPE_ALL is set then all input chars will be output using
"\x01F1" style escapes, otherwise if PERL_PV_ESCAPE_NONASCII is
set, only non-ASCII chars will be escaped using this style; otherwise,
only chars above 255 will be so escaped; other non printable chars will
use octal or common escaped patterns like "\n". Otherwise, if
PERL_PV_ESCAPE_NOBACKSLASH then all chars below 255 will be treated as
printable and will be output as literals.
If PERL_PV_ESCAPE_FIRSTCHAR is set then only the first char of the string
will be escaped, regardless of max. If the output is to be in hex, then it
will be returned as a plain hex sequence. Thus the output will either be a
single char, an octal escape sequence, a special escape like
"\n" or a hex value.
If PERL_PV_ESCAPE_RE is set then the escape char used will be a '%' and not
a '\\'. This is because regexes very often contain backslashed sequences,
whereas '%' is not a particularly common character in patterns.
Returns a pointer to the escaped text as held by dsv.
char* pv_escape(SV *dsv, char const * const str,
const STRLEN count, const STRLEN max,
STRLEN * const escaped,
const U32 flags)
- pv_pretty
- Converts a string into something presentable, handling escaping via
pv_escape() and supporting quoting and ellipses.
If the PERL_PV_PRETTY_QUOTE flag is set then the result will be double
quoted with any double quotes in the string escaped. Otherwise if the
PERL_PV_PRETTY_LTGT flag is set then the result be wrapped in angle
brackets.
If the PERL_PV_PRETTY_ELLIPSES flag is set and not all characters in string
were output then an ellipsis "..." will be appended to the
string. Note that this happens AFTER it has been quoted.
If start_color is non-null then it will be inserted after the opening quote
(if there is one) but before the escaped text. If end_color is non-null
then it will be inserted after the escaped text but before any quotes or
ellipses.
Returns a pointer to the prettified text as held by dsv.
char* pv_pretty(SV *dsv, char const * const str,
const STRLEN count, const STRLEN max,
char const * const start_color,
char const * const end_color,
const U32 flags)
Functions in file inline.h¶
- is_safe_syscall
- Test that the given "pv" doesn't contain any internal
"NUL" characters. If it does, set "errno" to ENOENT,
optionally warn, and return FALSE.
Return TRUE if the name is safe.
Used by the IS_SAFE_SYSCALL() macro.
bool is_safe_syscall(const char *pv, STRLEN len,
const char *what,
const char *op_name)
Functions in file mathoms.c¶
- custom_op_desc
- Return the description of a given custom op. This was once used by the
OP_DESC macro, but is no longer: it has only been kept for compatibility,
and should not be used.
const char * custom_op_desc(const OP *o)
- custom_op_name
- Return the name for a given custom op. This was once used by the OP_NAME
macro, but is no longer: it has only been kept for compatibility, and
should not be used.
const char * custom_op_name(const OP *o)
- gv_fetchmethod
- See "gv_fetchmethod_autoload".
GV* gv_fetchmethod(HV* stash, const char* name)
- pack_cat
- The engine implementing pack() Perl function. Note: parameters
next_in_list and flags are not used. This call should not be used; use
packlist instead.
void pack_cat(SV *cat, const char *pat,
const char *patend, SV **beglist,
SV **endlist, SV ***next_in_list,
U32 flags)
- sv_2pvbyte_nolen
- Return a pointer to the byte-encoded representation of the SV. May cause
the SV to be downgraded from UTF-8 as a side-effect.
Usually accessed via the "SvPVbyte_nolen" macro.
char* sv_2pvbyte_nolen(SV* sv)
- sv_2pvutf8_nolen
- Return a pointer to the UTF-8-encoded representation of the SV. May cause
the SV to be upgraded to UTF-8 as a side-effect.
Usually accessed via the "SvPVutf8_nolen" macro.
char* sv_2pvutf8_nolen(SV* sv)
- sv_2pv_nolen
- Like "sv_2pv()", but doesn't return the length too. You should
usually use the macro wrapper "SvPV_nolen(sv)" instead.
char* sv_2pv_nolen(SV* sv)
- sv_catpvn_mg
- Like "sv_catpvn", but also handles 'set' magic.
void sv_catpvn_mg(SV *sv, const char *ptr,
STRLEN len)
- sv_catsv_mg
- Like "sv_catsv", but also handles 'set' magic.
void sv_catsv_mg(SV *dsv, SV *ssv)
- sv_force_normal
- Undo various types of fakery on an SV: if the PV is a shared string, make
a private copy; if we're a ref, stop refing; if we're a glob, downgrade to
an xpvmg. See also "sv_force_normal_flags".
void sv_force_normal(SV *sv)
- sv_iv
- A private implementation of the "SvIVx" macro for compilers
which can't cope with complex macro expressions. Always use the macro
instead.
IV sv_iv(SV* sv)
- sv_nolocking
- Dummy routine which "locks" an SV when there is no locking
module present. Exists to avoid test for a NULL function pointer and
because it could potentially warn under some level of strict-ness.
"Superseded" by sv_nosharing().
void sv_nolocking(SV *sv)
- sv_nounlocking
- Dummy routine which "unlocks" an SV when there is no locking
module present. Exists to avoid test for a NULL function pointer and
because it could potentially warn under some level of strict-ness.
"Superseded" by sv_nosharing().
void sv_nounlocking(SV *sv)
- sv_nv
- A private implementation of the "SvNVx" macro for compilers
which can't cope with complex macro expressions. Always use the macro
instead.
NV sv_nv(SV* sv)
- sv_pv
- Use the "SvPV_nolen" macro instead
char* sv_pv(SV *sv)
- sv_pvbyte
- Use "SvPVbyte_nolen" instead.
char* sv_pvbyte(SV *sv)
- sv_pvbyten
- A private implementation of the "SvPVbyte" macro for compilers
which can't cope with complex macro expressions. Always use the macro
instead.
char* sv_pvbyten(SV *sv, STRLEN *lp)
- sv_pvn
- A private implementation of the "SvPV" macro for compilers which
can't cope with complex macro expressions. Always use the macro instead.
char* sv_pvn(SV *sv, STRLEN *lp)
- sv_pvutf8
- Use the "SvPVutf8_nolen" macro instead
char* sv_pvutf8(SV *sv)
- sv_pvutf8n
- A private implementation of the "SvPVutf8" macro for compilers
which can't cope with complex macro expressions. Always use the macro
instead.
char* sv_pvutf8n(SV *sv, STRLEN *lp)
- sv_taint
- Taint an SV. Use "SvTAINTED_on" instead.
void sv_taint(SV* sv)
- sv_unref
- Unsets the RV status of the SV, and decrements the reference count of
whatever was being referenced by the RV. This can almost be thought of as
a reversal of "newSVrv". This is "sv_unref_flags" with
the "flag" being zero. See "SvROK_off".
void sv_unref(SV* sv)
- sv_usepvn
- Tells an SV to use "ptr" to find its string value. Implemented
by calling "sv_usepvn_flags" with "flags" of 0, hence
does not handle 'set' magic. See "sv_usepvn_flags".
void sv_usepvn(SV* sv, char* ptr, STRLEN len)
- sv_usepvn_mg
- Like "sv_usepvn", but also handles 'set' magic.
void sv_usepvn_mg(SV *sv, char *ptr, STRLEN len)
- sv_uv
- A private implementation of the "SvUVx" macro for compilers
which can't cope with complex macro expressions. Always use the macro
instead.
UV sv_uv(SV* sv)
- unpack_str
- The engine implementing unpack() Perl function. Note: parameters
strbeg, new_s and ocnt are not used. This call should not be used, use
unpackstring instead.
I32 unpack_str(const char *pat, const char *patend,
const char *s, const char *strbeg,
const char *strend, char **new_s,
I32 ocnt, U32 flags)
Functions in file op.c¶
- alloccopstash
- NOTE: this function is experimental and may change or be removed without
notice.
Available only under threaded builds, this function allocates an entry in
"PL_stashpad" for the stash passed to it.
PADOFFSET alloccopstash(HV *hv)
- op_contextualize
- Applies a syntactic context to an op tree representing an expression.
o is the op tree, and context must be "G_SCALAR",
"G_ARRAY", or "G_VOID" to specify the context to
apply. The modified op tree is returned.
OP * op_contextualize(OP *o, I32 context)
- op_free
- Free an op. Only use this when an op is no longer linked to from any
optree.
void op_free(OP *o)
- op_null
- Neutralizes an op when it is no longer needed, but is still linked to from
other ops.
void op_null(OP *o)
Functions in file perl.h¶
- PERL_SYS_INIT
- Provides system-specific tune up of the C runtime environment necessary to
run Perl interpreters. This should be called only once, before creating
any Perl interpreters.
void PERL_SYS_INIT(int *argc, char*** argv)
- PERL_SYS_INIT3
- Provides system-specific tune up of the C runtime environment necessary to
run Perl interpreters. This should be called only once, before creating
any Perl interpreters.
void PERL_SYS_INIT3(int *argc, char*** argv,
char*** env)
- PERL_SYS_TERM
- Provides system-specific clean up of the C runtime environment after
running Perl interpreters. This should be called only once, after freeing
any remaining Perl interpreters.
void PERL_SYS_TERM()
Functions in file pp_ctl.c¶
- caller_cx
- The XSUB-writer's equivalent of caller(). The returned
"PERL_CONTEXT" structure can be interrogated to find all the
information returned to Perl by "caller". Note that XSUBs don't
get a stack frame, so "caller_cx(0, NULL)" will return
information for the immediately-surrounding Perl code.
This function skips over the automatic calls to &DB::sub made on the
behalf of the debugger. If the stack frame requested was a sub called by
"DB::sub", the return value will be the frame for the call to
"DB::sub", since that has the correct line number/etc. for the
call site. If dbcxp is non-"NULL", it will be set to a
pointer to the frame for the sub call itself.
const PERL_CONTEXT * caller_cx(
I32 level,
const PERL_CONTEXT **dbcxp
)
- find_runcv
- Locate the CV corresponding to the currently executing sub or eval. If
db_seqp is non_null, skip CVs that are in the DB package and populate
*db_seqp with the cop sequence number at the point that the DB:: code was
entered. (This allows debuggers to eval in the scope of the breakpoint
rather than in the scope of the debugger itself.)
CV* find_runcv(U32 *db_seqp)
Functions in file pp_pack.c¶
- packlist
- The engine implementing pack() Perl function.
void packlist(SV *cat, const char *pat,
const char *patend, SV **beglist,
SV **endlist)
- unpackstring
- The engine implementing the unpack() Perl function.
Using the template pat..patend, this function unpacks the string s..strend
into a number of mortal SVs, which it pushes onto the perl argument (@_)
stack (so you will need to issue a "PUTBACK" before and
"SPAGAIN" after the call to this function). It returns the
number of pushed elements.
The strend and patend pointers should point to the byte following the last
character of each string.
Although this function returns its values on the perl argument stack, it
doesn't take any parameters from that stack (and thus in particular
there's no need to do a PUSHMARK before calling it, unlike
"call_pv" for example).
I32 unpackstring(const char *pat,
const char *patend, const char *s,
const char *strend, U32 flags)
Functions in file pp_sys.c¶
- setdefout
- Sets PL_defoutgv, the default file handle for output, to the passed in
typeglob. As PL_defoutgv "owns" a reference on its typeglob, the
reference count of the passed in typeglob is increased by one, and the
reference count of the typeglob that PL_defoutgv points to is decreased by
one.
void setdefout(GV* gv)
Functions in file utf8.h¶
- ibcmp_utf8
- This is a synonym for (! foldEQ_utf8())
I32 ibcmp_utf8(const char *s1, char **pe1, UV l1,
bool u1, const char *s2, char **pe2,
UV l2, bool u2)
Functions in file util.h¶
- ibcmp
- This is a synonym for (! foldEQ())
I32 ibcmp(const char* a, const char* b, I32 len)
- ibcmp_locale
- This is a synonym for (! foldEQ_locale())
I32 ibcmp_locale(const char* a, const char* b,
I32 len)
Functions in file vutil.c¶
- new_version
- Returns a new version object based on the passed in SV:
SV *sv = new_version(SV *ver);
Does not alter the passed in ver SV. See "upg_version" if you want
to upgrade the SV.
SV* new_version(SV *ver)
- prescan_version
- Validate that a given string can be parsed as a version object, but
doesn't actually perform the parsing. Can use either strict or lax
validation rules. Can optionally set a number of hint variables to save
the parsing code some time when tokenizing.
const char* prescan_version(const char *s, bool strict,
const char** errstr,
bool *sqv,
int *ssaw_decimal,
int *swidth, bool *salpha)
- scan_version
- Returns a pointer to the next character after the parsed version string,
as well as upgrading the passed in SV to an RV.
Function must be called with an already existing SV like
sv = newSV(0);
s = scan_version(s, SV *sv, bool qv);
Performs some preprocessing to the string to ensure that it has the correct
characteristics of a version. Flags the object if it contains an
underscore (which denotes this is an alpha version). The boolean qv
denotes that the version should be interpreted as if it had multiple
decimals, even if it doesn't.
const char* scan_version(const char *s, SV *rv, bool qv)
- upg_version
- In-place upgrade of the supplied SV to a version object.
SV *sv = upg_version(SV *sv, bool qv);
Returns a pointer to the upgraded SV. Set the boolean qv if you want to
force this SV to be interpreted as an "extended" version.
SV* upg_version(SV *ver, bool qv)
- vcmp
- Version object aware cmp. Both operands must already have been converted
into version objects.
int vcmp(SV *lhv, SV *rhv)
- vnormal
- Accepts a version object and returns the normalized string representation.
Call like:
sv = vnormal(rv);
NOTE: you can pass either the object directly or the SV contained within the
RV.
The SV returned has a refcount of 1.
SV* vnormal(SV *vs)
- vnumify
- Accepts a version object and returns the normalized floating point
representation. Call like:
sv = vnumify(rv);
NOTE: you can pass either the object directly or the SV contained within the
RV.
The SV returned has a refcount of 1.
SV* vnumify(SV *vs)
- vstringify
- In order to maintain maximum compatibility with earlier versions of Perl,
this function will return either the floating point notation or the
multiple dotted notation, depending on whether the original version
contained 1 or more dots, respectively.
The SV returned has a refcount of 1.
SV* vstringify(SV *vs)
- vverify
- Validates that the SV contains valid internal structure for a version
object. It may be passed either the version object (RV) or the hash itself
(HV). If the structure is valid, it returns the HV. If the structure is
invalid, it returns NULL.
SV *hv = vverify(sv);
Note that it only confirms the bare minimum structure (so as not to get
confused by derived classes which may contain additional hash entries):
SV* vverify(SV *vs)
Global Variables¶
- PL_check
- Array, indexed by opcode, of functions that will be called for the
"check" phase of optree building during compilation of Perl
code. For most (but not all) types of op, once the op has been initially
built and populated with child ops it will be filtered through the check
function referenced by the appropriate element of this array. The new op
is passed in as the sole argument to the check function, and the check
function returns the completed op. The check function may (as the name
suggests) check the op for validity and signal errors. It may also
initialise or modify parts of the ops, or perform more radical surgery
such as adding or removing child ops, or even throw the op away and return
a different op in its place.
This array of function pointers is a convenient place to hook into the
compilation process. An XS module can put its own custom check function in
place of any of the standard ones, to influence the compilation of a
particular type of op. However, a custom check function must never fully
replace a standard check function (or even a custom check function from
another module). A module modifying checking must instead wrap the
preexisting check function. A custom check function must be selective
about when to apply its custom behaviour. In the usual case where it
decides not to do anything special with an op, it must chain the
preexisting op function. Check functions are thus linked in a chain, with
the core's base checker at the end.
For thread safety, modules should not write directly to this array. Instead,
use the function "wrap_op_checker".
- PL_keyword_plugin
- NOTE: this function is experimental and may change or be removed without
notice.
Function pointer, pointing at a function used to handle extended keywords.
The function should be declared as
int keyword_plugin_function(pTHX_
char *keyword_ptr, STRLEN keyword_len,
OP **op_ptr)
The function is called from the tokeniser, whenever a possible keyword is
seen. "keyword_ptr" points at the word in the parser's input
buffer, and "keyword_len" gives its length; it is not
null-terminated. The function is expected to examine the word, and
possibly other state such as %^H, to decide whether it wants to handle it
as an extended keyword. If it does not, the function should return
"KEYWORD_PLUGIN_DECLINE", and the normal parser process will
continue.
If the function wants to handle the keyword, it first must parse anything
following the keyword that is part of the syntax introduced by the
keyword. See "Lexer interface" for details.
When a keyword is being handled, the plugin function must build a tree of
"OP" structures, representing the code that was parsed. The root
of the tree must be stored in *op_ptr. The function then returns a
constant indicating the syntactic role of the construct that it has
parsed: "KEYWORD_PLUGIN_STMT" if it is a complete statement, or
"KEYWORD_PLUGIN_EXPR" if it is an expression. Note that a
statement construct cannot be used inside an expression (except via
"do BLOCK" and similar), and an expression is not a complete
statement (it requires at least a terminating semicolon).
When a keyword is handled, the plugin function may also have (compile-time)
side effects. It may modify "%^H", define functions, and so on.
Typically, if side effects are the main purpose of a handler, it does not
wish to generate any ops to be included in the normal compilation. In this
case it is still required to supply an op tree, but it suffices to
generate a single null op.
That's how the *PL_keyword_plugin function needs to behave overall.
Conventionally, however, one does not completely replace the existing
handler function. Instead, take a copy of "PL_keyword_plugin"
before assigning your own function pointer to it. Your handler function
should look for keywords that it is interested in and handle those. Where
it is not interested, it should call the saved plugin function, passing on
the arguments it received. Thus "PL_keyword_plugin" actually
points at a chain of handler functions, all of which have an opportunity
to handle keywords, and only the last function in the chain (built into
the Perl core) will normally return
"KEYWORD_PLUGIN_DECLINE".
GV Functions¶
- GvAV
- Return the AV from the GV.
AV* GvAV(GV* gv)
- GvCV
- Return the CV from the GV.
CV* GvCV(GV* gv)
- GvHV
- Return the HV from the GV.
HV* GvHV(GV* gv)
- GvSV
- Return the SV from the GV.
SV* GvSV(GV* gv)
- gv_const_sv
- If "gv" is a typeglob whose subroutine entry is a constant sub
eligible for inlining, or "gv" is a placeholder reference that
would be promoted to such a typeglob, then returns the value returned by
the sub. Otherwise, returns NULL.
SV* gv_const_sv(GV* gv)
- gv_fetchmeth
- Like "gv_fetchmeth_pvn", but lacks a flags parameter.
GV* gv_fetchmeth(HV* stash, const char* name,
STRLEN len, I32 level)
- gv_fetchmethod_autoload
- Returns the glob which contains the subroutine to call to invoke the
method on the "stash". In fact in the presence of autoloading
this may be the glob for "AUTOLOAD". In this case the
corresponding variable $AUTOLOAD is already setup.
The third parameter of "gv_fetchmethod_autoload" determines
whether AUTOLOAD lookup is performed if the given method is not present:
non-zero means yes, look for AUTOLOAD; zero means no, don't look for
AUTOLOAD. Calling "gv_fetchmethod" is equivalent to calling
"gv_fetchmethod_autoload" with a non-zero "autoload"
parameter.
These functions grant "SUPER" token as a prefix of the method
name. Note that if you want to keep the returned glob for a long time, you
need to check for it being "AUTOLOAD", since at the later time
the call may load a different subroutine due to $AUTOLOAD changing its
value. Use the glob created as a side effect to do this.
These functions have the same side-effects as "gv_fetchmeth" with
"level==0". The warning against passing the GV returned by
"gv_fetchmeth" to "call_sv" applies equally to these
functions.
GV* gv_fetchmethod_autoload(HV* stash,
const char* name,
I32 autoload)
- gv_fetchmeth_autoload
- This is the old form of "gv_fetchmeth_pvn_autoload", which has
no flags parameter.
GV* gv_fetchmeth_autoload(HV* stash,
const char* name,
STRLEN len, I32 level)
- gv_fetchmeth_pv
- Exactly like "gv_fetchmeth_pvn", but takes a nul-terminated
string instead of a string/length pair.
GV* gv_fetchmeth_pv(HV* stash, const char* name,
I32 level, U32 flags)
- gv_fetchmeth_pvn
- Returns the glob with the given "name" and a defined subroutine
or "NULL". The glob lives in the given "stash", or in
the stashes accessible via @ISA and UNIVERSAL::.
The argument "level" should be either 0 or -1. If
"level==0", as a side-effect creates a glob with the given
"name" in the given "stash" which in the case of
success contains an alias for the subroutine, and sets up caching info for
this glob.
The only significant values for "flags" are GV_SUPER and SVf_UTF8.
GV_SUPER indicates that we want to look up the method in the superclasses of
the "stash".
The GV returned from "gv_fetchmeth" may be a method cache entry,
which is not visible to Perl code. So when calling "call_sv",
you should not use the GV directly; instead, you should use the method's
CV, which can be obtained from the GV with the "GvCV" macro.
GV* gv_fetchmeth_pvn(HV* stash, const char* name,
STRLEN len, I32 level,
U32 flags)
- gv_fetchmeth_pvn_autoload
- Same as gv_fetchmeth_pvn(), but looks for autoloaded subroutines
too. Returns a glob for the subroutine.
For an autoloaded subroutine without a GV, will create a GV even if
"level < 0". For an autoloaded subroutine without a stub,
GvCV() of the result may be zero.
Currently, the only significant value for "flags" is SVf_UTF8.
GV* gv_fetchmeth_pvn_autoload(HV* stash,
const char* name,
STRLEN len, I32 level,
U32 flags)
- gv_fetchmeth_pv_autoload
- Exactly like "gv_fetchmeth_pvn_autoload", but takes a
nul-terminated string instead of a string/length pair.
GV* gv_fetchmeth_pv_autoload(HV* stash,
const char* name,
I32 level, U32 flags)
- gv_fetchmeth_sv
- Exactly like "gv_fetchmeth_pvn", but takes the name string in
the form of an SV instead of a string/length pair.
GV* gv_fetchmeth_sv(HV* stash, SV* namesv,
I32 level, U32 flags)
- gv_fetchmeth_sv_autoload
- Exactly like "gv_fetchmeth_pvn_autoload", but takes the name
string in the form of an SV instead of a string/length pair.
GV* gv_fetchmeth_sv_autoload(HV* stash, SV* namesv,
I32 level, U32 flags)
- gv_init
- The old form of gv_init_pvn(). It does not work with UTF8 strings,
as it has no flags parameter. If the "multi" parameter is set,
the GV_ADDMULTI flag will be passed to gv_init_pvn().
void gv_init(GV* gv, HV* stash, const char* name,
STRLEN len, int multi)
- gv_init_pv
- Same as gv_init_pvn(), but takes a nul-terminated string for the
name instead of separate char * and length parameters.
void gv_init_pv(GV* gv, HV* stash, const char* name,
U32 flags)
- gv_init_pvn
- Converts a scalar into a typeglob. This is an incoercible typeglob;
assigning a reference to it will assign to one of its slots, instead of
overwriting it as happens with typeglobs created by SvSetSV. Converting
any scalar that is SvOK() may produce unpredictable results and is
reserved for perl's internal use.
"gv" is the scalar to be converted.
"stash" is the parent stash/package, if any.
"name" and "len" give the name. The name must be
unqualified; that is, it must not include the package name. If
"gv" is a stash element, it is the caller's responsibility to
ensure that the name passed to this function matches the name of the
element. If it does not match, perl's internal bookkeeping will get out of
sync.
"flags" can be set to SVf_UTF8 if "name" is a UTF8
string, or the return value of SvUTF8(sv). It can also take the
GV_ADDMULTI flag, which means to pretend that the GV has been seen before
(i.e., suppress "Used once" warnings).
void gv_init_pvn(GV* gv, HV* stash, const char* name,
STRLEN len, U32 flags)
- gv_init_sv
- Same as gv_init_pvn(), but takes an SV * for the name instead of
separate char * and length parameters. "flags" is currently
unused.
void gv_init_sv(GV* gv, HV* stash, SV* namesv,
U32 flags)
- gv_stashpv
- Returns a pointer to the stash for a specified package. Uses
"strlen" to determine the length of "name", then calls
"gv_stashpvn()".
HV* gv_stashpv(const char* name, I32 flags)
- gv_stashpvn
- Returns a pointer to the stash for a specified package. The
"namelen" parameter indicates the length of the
"name", in bytes. "flags" is passed to
"gv_fetchpvn_flags()", so if set to "GV_ADD" then the
package will be created if it does not already exist. If the package does
not exist and "flags" is 0 (or any other setting that does not
create packages) then NULL is returned.
Flags may be one of:
GV_ADD
SVf_UTF8
GV_NOADD_NOINIT
GV_NOINIT
GV_NOEXPAND
GV_ADDMG
The most important of which are probably GV_ADD and SVf_UTF8.
HV* gv_stashpvn(const char* name, U32 namelen,
I32 flags)
- gv_stashpvs
- Like "gv_stashpvn", but takes a literal string instead of a
string/length pair.
HV* gv_stashpvs(const char* name, I32 create)
- gv_stashsv
- Returns a pointer to the stash for a specified package. See
"gv_stashpvn".
HV* gv_stashsv(SV* sv, I32 flags)
Handy Values¶
- Nullav
- Null AV pointer.
(deprecated - use "(AV *)NULL" instead)
- Nullch
- Null character pointer. (No longer available when "PERL_CORE" is
defined.)
- Nullcv
- Null CV pointer.
(deprecated - use "(CV *)NULL" instead)
- Nullhv
- Null HV pointer.
(deprecated - use "(HV *)NULL" instead)
- Nullsv
- Null SV pointer. (No longer available when "PERL_CORE" is
defined.)
Hash Manipulation Functions¶
- cop_fetch_label
- NOTE: this function is experimental and may change or be removed without
notice.
Returns the label attached to a cop. The flags pointer may be set to
"SVf_UTF8" or 0.
const char * cop_fetch_label(COP *const cop,
STRLEN *len, U32 *flags)
- cop_store_label
- NOTE: this function is experimental and may change or be removed without
notice.
Save a label into a "cop_hints_hash". You need to set flags to
"SVf_UTF8" for a utf-8 label.
void cop_store_label(COP *const cop,
const char *label, STRLEN len,
U32 flags)
- get_hv
- Returns the HV of the specified Perl hash. "flags" are passed to
"gv_fetchpv". If "GV_ADD" is set and the Perl variable
does not exist then it will be created. If "flags" is zero and
the variable does not exist then NULL is returned.
NOTE: the perl_ form of this function is deprecated.
HV* get_hv(const char *name, I32 flags)
- HEf_SVKEY
- This flag, used in the length slot of hash entries and magic structures,
specifies the structure contains an "SV*" pointer where a
"char*" pointer is to be expected. (For information only--not to
be used).
- HeHASH
- Returns the computed hash stored in the hash entry.
U32 HeHASH(HE* he)
- HeKEY
- Returns the actual pointer stored in the key slot of the hash entry. The
pointer may be either "char*" or "SV*", depending on
the value of "HeKLEN()". Can be assigned to. The
"HePV()" or "HeSVKEY()" macros are usually preferable
for finding the value of a key.
void* HeKEY(HE* he)
- HeKLEN
- If this is negative, and amounts to "HEf_SVKEY", it indicates
the entry holds an "SV*" key. Otherwise, holds the actual length
of the key. Can be assigned to. The "HePV()" macro is usually
preferable for finding key lengths.
STRLEN HeKLEN(HE* he)
- HePV
- Returns the key slot of the hash entry as a "char*" value, doing
any necessary dereferencing of possibly "SV*" keys. The length
of the string is placed in "len" (this is a macro, so do
not use &len). If you do not care about what the length of the
key is, you may use the global variable "PL_na", though this is
rather less efficient than using a local variable. Remember though, that
hash keys in perl are free to contain embedded nulls, so using
"strlen()" or similar is not a good way to find the length of
hash keys. This is very similar to the "SvPV()" macro described
elsewhere in this document. See also "HeUTF8".
If you are using "HePV" to get values to pass to
"newSVpvn()" to create a new SV, you should consider using
"newSVhek(HeKEY_hek(he))" as it is more efficient.
char* HePV(HE* he, STRLEN len)
- HeSVKEY
- Returns the key as an "SV*", or "NULL" if the hash
entry does not contain an "SV*" key.
SV* HeSVKEY(HE* he)
- HeSVKEY_force
- Returns the key as an "SV*". Will create and return a temporary
mortal "SV*" if the hash entry contains only a "char*"
key.
SV* HeSVKEY_force(HE* he)
- HeSVKEY_set
- Sets the key to a given "SV*", taking care to set the
appropriate flags to indicate the presence of an "SV*" key, and
returns the same "SV*".
SV* HeSVKEY_set(HE* he, SV* sv)
- HeUTF8
- Returns whether the "char *" value returned by "HePV"
is encoded in UTF-8, doing any necessary dereferencing of possibly
"SV*" keys. The value returned will be 0 or non-0, not
necessarily 1 (or even a value with any low bits set), so do not
blindly assign this to a "bool" variable, as "bool"
may be a typedef for "char".
U32 HeUTF8(HE* he)
- HeVAL
- Returns the value slot (type "SV*") stored in the hash entry.
Can be assigned to.
SV *foo= HeVAL(hv);
HeVAL(hv)= sv;
SV* HeVAL(HE* he)
- HvENAME
- Returns the effective name of a stash, or NULL if there is none. The
effective name represents a location in the symbol table where this stash
resides. It is updated automatically when packages are aliased or deleted.
A stash that is no longer in the symbol table has no effective name. This
name is preferable to "HvNAME" for use in MRO linearisations and
isa caches.
char* HvENAME(HV* stash)
- HvENAMELEN
- Returns the length of the stash's effective name.
STRLEN HvENAMELEN(HV *stash)
- HvENAMEUTF8
- Returns true if the effective name is in UTF8 encoding.
unsigned char HvENAMEUTF8(HV *stash)
- HvNAME
- Returns the package name of a stash, or NULL if "stash" isn't a
stash. See "SvSTASH", "CvSTASH".
char* HvNAME(HV* stash)
- HvNAMELEN
- Returns the length of the stash's name.
STRLEN HvNAMELEN(HV *stash)
- HvNAMEUTF8
- Returns true if the name is in UTF8 encoding.
unsigned char HvNAMEUTF8(HV *stash)
- hv_assert
- Check that a hash is in an internally consistent state.
void hv_assert(HV *hv)
- hv_clear
- Frees the all the elements of a hash, leaving it empty. The XS equivalent
of "%hash = ()". See also "hv_undef".
If any destructors are triggered as a result, the hv itself may be freed.
void hv_clear(HV *hv)
- hv_clear_placeholders
- Clears any placeholders from a hash. If a restricted hash has any of its
keys marked as readonly and the key is subsequently deleted, the key is
not actually deleted but is marked by assigning it a value of
&PL_sv_placeholder. This tags it so it will be ignored by future
operations such as iterating over the hash, but will still allow the hash
to have a value reassigned to the key at some future point. This function
clears any such placeholder keys from the hash. See
Hash::Util::lock_keys() for an example of its use.
void hv_clear_placeholders(HV *hv)
- hv_copy_hints_hv
- A specialised version of "newHVhv" for copying "%^H".
ohv must be a pointer to a hash (which may have "%^H"
magic, but should be generally non-magical), or "NULL"
(interpreted as an empty hash). The content of ohv is copied to a
new hash, which has the "%^H"-specific magic added to it. A
pointer to the new hash is returned.
HV * hv_copy_hints_hv(HV *ohv)
- hv_delete
- Deletes a key/value pair in the hash. The value's SV is removed from the
hash, made mortal, and returned to the caller. The absolute value of
"klen" is the length of the key. If "klen" is negative
the key is assumed to be in UTF-8-encoded Unicode. The "flags"
value will normally be zero; if set to G_DISCARD then NULL will be
returned. NULL will also be returned if the key is not found.
SV* hv_delete(HV *hv, const char *key, I32 klen,
I32 flags)
- hv_delete_ent
- Deletes a key/value pair in the hash. The value SV is removed from the
hash, made mortal, and returned to the caller. The "flags" value
will normally be zero; if set to G_DISCARD then NULL will be returned.
NULL will also be returned if the key is not found. "hash" can
be a valid precomputed hash value, or 0 to ask for it to be computed.
SV* hv_delete_ent(HV *hv, SV *keysv, I32 flags,
U32 hash)
- hv_exists
- Returns a boolean indicating whether the specified hash key exists. The
absolute value of "klen" is the length of the key. If
"klen" is negative the key is assumed to be in UTF-8-encoded
Unicode.
bool hv_exists(HV *hv, const char *key, I32 klen)
- hv_exists_ent
- Returns a boolean indicating whether the specified hash key exists.
"hash" can be a valid precomputed hash value, or 0 to ask for it
to be computed.
bool hv_exists_ent(HV *hv, SV *keysv, U32 hash)
- hv_fetch
- Returns the SV which corresponds to the specified key in the hash. The
absolute value of "klen" is the length of the key. If
"klen" is negative the key is assumed to be in UTF-8-encoded
Unicode. If "lval" is set then the fetch will be part of a
store. This means that if there is no value in the hash associated with
the given key, then one is created and a pointer to it is returned. The
"SV*" it points to can be assigned to. But always check that the
return value is non-null before dereferencing it to an "SV*".
See "Understanding the Magic of Tied Hashes and Arrays" in
perlguts for more information on how to use this function on tied hashes.
SV** hv_fetch(HV *hv, const char *key, I32 klen,
I32 lval)
- hv_fetchs
- Like "hv_fetch", but takes a literal string instead of a
string/length pair.
SV** hv_fetchs(HV* tb, const char* key, I32 lval)
- hv_fetch_ent
- Returns the hash entry which corresponds to the specified key in the hash.
"hash" must be a valid precomputed hash number for the given
"key", or 0 if you want the function to compute it. IF
"lval" is set then the fetch will be part of a store. Make sure
the return value is non-null before accessing it. The return value when
"hv" is a tied hash is a pointer to a static location, so be
sure to make a copy of the structure if you need to store it somewhere.
See "Understanding the Magic of Tied Hashes and Arrays" in
perlguts for more information on how to use this function on tied hashes.
HE* hv_fetch_ent(HV *hv, SV *keysv, I32 lval,
U32 hash)
- hv_fill
- Returns the number of hash buckets that happen to be in use. This function
is wrapped by the macro "HvFILL".
Previously this value was always stored in the HV structure, which created
an overhead on every hash (and pretty much every object) for something
that was rarely used. Now we calculate it on demand the first time that it
is needed, and cache it if that calculation is going to be costly to
repeat. The cached value is updated by insertions and deletions, but
(currently) discarded if the hash is split.
STRLEN hv_fill(HV *const hv)
- hv_iterinit
- Prepares a starting point to traverse a hash table. Returns the number of
keys in the hash (i.e. the same as "HvUSEDKEYS(hv)"). The return
value is currently only meaningful for hashes without tie magic.
NOTE: Before version 5.004_65, "hv_iterinit" used to return the
number of hash buckets that happen to be in use. If you still need that
esoteric value, you can get it through the macro "HvFILL(hv)".
I32 hv_iterinit(HV *hv)
- hv_iterkey
- Returns the key from the current position of the hash iterator. See
"hv_iterinit".
char* hv_iterkey(HE* entry, I32* retlen)
- hv_iterkeysv
- Returns the key as an "SV*" from the current position of the
hash iterator. The return value will always be a mortal copy of the key.
Also see "hv_iterinit".
SV* hv_iterkeysv(HE* entry)
- hv_iternext
- Returns entries from a hash iterator. See "hv_iterinit".
You may call "hv_delete" or "hv_delete_ent" on the hash
entry that the iterator currently points to, without losing your place or
invalidating your iterator. Note that in this case the current entry is
deleted from the hash with your iterator holding the last reference to it.
Your iterator is flagged to free the entry on the next call to
"hv_iternext", so you must not discard your iterator immediately
else the entry will leak - call "hv_iternext" to trigger the
resource deallocation.
HE* hv_iternext(HV *hv)
- hv_iternextsv
- Performs an "hv_iternext", "hv_iterkey", and
"hv_iterval" in one operation.
SV* hv_iternextsv(HV *hv, char **key, I32 *retlen)
- hv_iternext_flags
- NOTE: this function is experimental and may change or be removed without
notice.
Returns entries from a hash iterator. See "hv_iterinit" and
"hv_iternext". The "flags" value will normally be
zero; if HV_ITERNEXT_WANTPLACEHOLDERS is set the placeholders keys (for
restricted hashes) will be returned in addition to normal keys. By default
placeholders are automatically skipped over. Currently a placeholder is
implemented with a value that is &PL_sv_placeholder. Note that the
implementation of placeholders and restricted hashes may change, and the
implementation currently is insufficiently abstracted for any change to be
tidy.
HE* hv_iternext_flags(HV *hv, I32 flags)
- hv_iterval
- Returns the value from the current position of the hash iterator. See
"hv_iterkey".
SV* hv_iterval(HV *hv, HE *entry)
- hv_magic
- Adds magic to a hash. See "sv_magic".
void hv_magic(HV *hv, GV *gv, int how)
- hv_scalar
- Evaluates the hash in scalar context and returns the result. Handles magic
when the hash is tied.
SV* hv_scalar(HV *hv)
- hv_store
- Stores an SV in a hash. The hash key is specified as "key" and
the absolute value of "klen" is the length of the key. If
"klen" is negative the key is assumed to be in UTF-8-encoded
Unicode. The "hash" parameter is the precomputed hash value; if
it is zero then Perl will compute it.
The return value will be NULL if the operation failed or if the value did
not need to be actually stored within the hash (as in the case of tied
hashes). Otherwise it can be dereferenced to get the original
"SV*". Note that the caller is responsible for suitably
incrementing the reference count of "val" before the call, and
decrementing it if the function returned NULL. Effectively a successful
hv_store takes ownership of one reference to "val". This is
usually what you want; a newly created SV has a reference count of one, so
if all your code does is create SVs then store them in a hash, hv_store
will own the only reference to the new SV, and your code doesn't need to
do anything further to tidy up. hv_store is not implemented as a call to
hv_store_ent, and does not create a temporary SV for the key, so if your
key data is not already in SV form then use hv_store in preference to
hv_store_ent.
See "Understanding the Magic of Tied Hashes and Arrays" in
perlguts for more information on how to use this function on tied hashes.
SV** hv_store(HV *hv, const char *key, I32 klen,
SV *val, U32 hash)
- hv_stores
- Like "hv_store", but takes a literal string instead of a
string/length pair and omits the hash parameter.
SV** hv_stores(HV* tb, const char* key,
NULLOK SV* val)
- hv_store_ent
- Stores "val" in a hash. The hash key is specified as
"key". The "hash" parameter is the precomputed hash
value; if it is zero then Perl will compute it. The return value is the
new hash entry so created. It will be NULL if the operation failed or if
the value did not need to be actually stored within the hash (as in the
case of tied hashes). Otherwise the contents of the return value can be
accessed using the "He?" macros described here. Note that the
caller is responsible for suitably incrementing the reference count of
"val" before the call, and decrementing it if the function
returned NULL. Effectively a successful hv_store_ent takes ownership of
one reference to "val". This is usually what you want; a newly
created SV has a reference count of one, so if all your code does is
create SVs then store them in a hash, hv_store will own the only reference
to the new SV, and your code doesn't need to do anything further to tidy
up. Note that hv_store_ent only reads the "key"; unlike
"val" it does not take ownership of it, so maintaining the
correct reference count on "key" is entirely the caller's
responsibility. hv_store is not implemented as a call to hv_store_ent, and
does not create a temporary SV for the key, so if your key data is not
already in SV form then use hv_store in preference to hv_store_ent.
See "Understanding the Magic of Tied Hashes and Arrays" in
perlguts for more information on how to use this function on tied hashes.
HE* hv_store_ent(HV *hv, SV *key, SV *val, U32 hash)
- hv_undef
- Undefines the hash. The XS equivalent of "undef(%hash)".
As well as freeing all the elements of the hash (like hv_clear()),
this also frees any auxiliary data and storage associated with the hash.
If any destructors are triggered as a result, the hv itself may be freed.
See also "hv_clear".
void hv_undef(HV *hv)
- newHV
- Creates a new HV. The reference count is set to 1.
HV* newHV()
Hook manipulation¶
- wrap_op_checker
- Puts a C function into the chain of check functions for a specified op
type. This is the preferred way to manipulate the "PL_check"
array. opcode specifies which type of op is to be affected.
new_checker is a pointer to the C function that is to be added to
that opcode's check chain, and old_checker_p points to the storage
location where a pointer to the next function in the chain will be stored.
The value of new_pointer is written into the "PL_check"
array, while the value previously stored there is written to
*old_checker_p.
The function should be defined like this:
static OP *new_checker(pTHX_ OP *op) { ... }
It is intended to be called in this manner:
new_checker(aTHX_ op)
old_checker_p should be defined like this:
static Perl_check_t old_checker_p;
"PL_check" is global to an entire process, and a module wishing to
hook op checking may find itself invoked more than once per process,
typically in different threads. To handle that situation, this function is
idempotent. The location *old_checker_p must initially (once per
process) contain a null pointer. A C variable of static duration (declared
at file scope, typically also marked "static" to give it
internal linkage) will be implicitly initialised appropriately, if it does
not have an explicit initialiser. This function will only actually modify
the check chain if it finds *old_checker_p to be null. This
function is also thread safe on the small scale. It uses appropriate
locking to avoid race conditions in accessing "PL_check".
When this function is called, the function referenced by new_checker
must be ready to be called, except for *old_checker_p being
unfilled. In a threading situation, new_checker may be called
immediately, even before this function has returned. *old_checker_p
will always be appropriately set before new_checker is called. If
new_checker decides not to do anything special with an op that it
is given (which is the usual case for most uses of op check hooking), it
must chain the check function referenced by *old_checker_p.
If you want to influence compilation of calls to a specific subroutine, then
use "cv_set_call_checker" rather than hooking checking of all
"entersub" ops.
void wrap_op_checker(Optype opcode,
Perl_check_t new_checker,
Perl_check_t *old_checker_p)
Lexer interface¶
- lex_bufutf8
- NOTE: this function is experimental and may change or be removed without
notice.
Indicates whether the octets in the lexer buffer
("PL_parser->linestr") should be interpreted as the UTF-8
encoding of Unicode characters. If not, they should be interpreted as
Latin-1 characters. This is analogous to the "SvUTF8" flag for
scalars.
In UTF-8 mode, it is not guaranteed that the lexer buffer actually contains
valid UTF-8. Lexing code must be robust in the face of invalid encoding.
The actual "SvUTF8" flag of the "PL_parser->linestr"
scalar is significant, but not the whole story regarding the input
character encoding. Normally, when a file is being read, the scalar
contains octets and its "SvUTF8" flag is off, but the octets
should be interpreted as UTF-8 if the "use utf8" pragma is in
effect. During a string eval, however, the scalar may have the
"SvUTF8" flag on, and in this case its octets should be
interpreted as UTF-8 unless the "use bytes" pragma is in effect.
This logic may change in the future; use this function instead of
implementing the logic yourself.
bool lex_bufutf8()
- lex_discard_to
- NOTE: this function is experimental and may change or be removed without
notice.
Discards the first part of the "PL_parser->linestr" buffer, up
to ptr. The remaining content of the buffer will be moved, and all
pointers into the buffer updated appropriately. ptr must not be
later in the buffer than the position of "PL_parser->bufptr":
it is not permitted to discard text that has yet to be lexed.
Normally it is not necessarily to do this directly, because it suffices to
use the implicit discarding behaviour of "lex_next_chunk" and
things based on it. However, if a token stretches across multiple lines,
and the lexing code has kept multiple lines of text in the buffer for that
purpose, then after completion of the token it would be wise to explicitly
discard the now-unneeded earlier lines, to avoid future multi-line tokens
growing the buffer without bound.
void lex_discard_to(char *ptr)
- lex_grow_linestr
- NOTE: this function is experimental and may change or be removed without
notice.
Reallocates the lexer buffer ("PL_parser->linestr") to
accommodate at least len octets (including terminating
"NUL"). Returns a pointer to the reallocated buffer. This is
necessary before making any direct modification of the buffer that would
increase its length. "lex_stuff_pvn" provides a more convenient
way to insert text into the buffer.
Do not use "SvGROW" or "sv_grow" directly on
"PL_parser->linestr"; this function updates all of the
lexer's variables that point directly into the buffer.
char * lex_grow_linestr(STRLEN len)
- lex_next_chunk
- NOTE: this function is experimental and may change or be removed without
notice.
Reads in the next chunk of text to be lexed, appending it to
"PL_parser->linestr". This should be called when lexing code
has looked to the end of the current chunk and wants to know more. It is
usual, but not necessary, for lexing to have consumed the entirety of the
current chunk at this time.
If "PL_parser->bufptr" is pointing to the very end of the
current chunk (i.e., the current chunk has been entirely consumed),
normally the current chunk will be discarded at the same time that the new
chunk is read in. If flags includes "LEX_KEEP_PREVIOUS",
the current chunk will not be discarded. If the current chunk has not been
entirely consumed, then it will not be discarded regardless of the flag.
Returns true if some new text was added to the buffer, or false if the
buffer has reached the end of the input text.
bool lex_next_chunk(U32 flags)
- lex_peek_unichar
- NOTE: this function is experimental and may change or be removed without
notice.
Looks ahead one (Unicode) character in the text currently being lexed.
Returns the codepoint (unsigned integer value) of the next character, or
-1 if lexing has reached the end of the input text. To consume the peeked
character, use "lex_read_unichar".
If the next character is in (or extends into) the next chunk of input text,
the next chunk will be read in. Normally the current chunk will be
discarded at the same time, but if flags includes
"LEX_KEEP_PREVIOUS" then the current chunk will not be
discarded.
If the input is being interpreted as UTF-8 and a UTF-8 encoding error is
encountered, an exception is generated.
I32 lex_peek_unichar(U32 flags)
- lex_read_space
- NOTE: this function is experimental and may change or be removed without
notice.
Reads optional spaces, in Perl style, in the text currently being lexed. The
spaces may include ordinary whitespace characters and Perl-style comments.
"#line" directives are processed if encountered.
"PL_parser->bufptr" is moved past the spaces, so that it
points at a non-space character (or the end of the input text).
If spaces extend into the next chunk of input text, the next chunk will be
read in. Normally the current chunk will be discarded at the same time,
but if flags includes "LEX_KEEP_PREVIOUS" then the
current chunk will not be discarded.
void lex_read_space(U32 flags)
- lex_read_to
- NOTE: this function is experimental and may change or be removed without
notice.
Consume text in the lexer buffer, from "PL_parser->bufptr" up
to ptr. This advances "PL_parser->bufptr" to match
ptr, performing the correct bookkeeping whenever a newline
character is passed. This is the normal way to consume lexed text.
Interpretation of the buffer's octets can be abstracted out by using the
slightly higher-level functions "lex_peek_unichar" and
"lex_read_unichar".
void lex_read_to(char *ptr)
- lex_read_unichar
- NOTE: this function is experimental and may change or be removed without
notice.
Reads the next (Unicode) character in the text currently being lexed.
Returns the codepoint (unsigned integer value) of the character read, and
moves "PL_parser->bufptr" past the character, or returns -1
if lexing has reached the end of the input text. To non-destructively
examine the next character, use "lex_peek_unichar" instead.
If the next character is in (or extends into) the next chunk of input text,
the next chunk will be read in. Normally the current chunk will be
discarded at the same time, but if flags includes
"LEX_KEEP_PREVIOUS" then the current chunk will not be
discarded.
If the input is being interpreted as UTF-8 and a UTF-8 encoding error is
encountered, an exception is generated.
I32 lex_read_unichar(U32 flags)
- lex_start
- NOTE: this function is experimental and may change or be removed without
notice.
Creates and initialises a new lexer/parser state object, supplying a context
in which to lex and parse from a new source of Perl code. A pointer to the
new state object is placed in "PL_parser". An entry is made on
the save stack so that upon unwinding the new state object will be
destroyed and the former value of "PL_parser" will be restored.
Nothing else need be done to clean up the parsing context.
The code to be parsed comes from line and rsfp. line,
if non-null, provides a string (in SV form) containing code to be parsed.
A copy of the string is made, so subsequent modification of line
does not affect parsing. rsfp, if non-null, provides an input
stream from which code will be read to be parsed. If both are non-null,
the code in line comes first and must consist of complete lines of
input, and rsfp supplies the remainder of the source.
The flags parameter is reserved for future use. Currently it is only
used by perl internally, so extensions should always pass zero.
void lex_start(SV *line, PerlIO *rsfp, U32 flags)
- lex_stuff_pv
- NOTE: this function is experimental and may change or be removed without
notice.
Insert characters into the lexer buffer ("PL_parser->linestr"),
immediately after the current lexing point
("PL_parser->bufptr"), reallocating the buffer if necessary.
This means that lexing code that runs later will see the characters as if
they had appeared in the input. It is not recommended to do this as part
of normal parsing, and most uses of this facility run the risk of the
inserted characters being interpreted in an unintended manner.
The string to be inserted is represented by octets starting at pv and
continuing to the first nul. These octets are interpreted as either UTF-8
or Latin-1, according to whether the "LEX_STUFF_UTF8" flag is
set in flags. The characters are recoded for the lexer buffer,
according to how the buffer is currently being interpreted
("lex_bufutf8"). If it is not convenient to nul-terminate a
string to be inserted, the "lex_stuff_pvn" function is more
appropriate.
void lex_stuff_pv(const char *pv, U32 flags)
- lex_stuff_pvn
- NOTE: this function is experimental and may change or be removed without
notice.
Insert characters into the lexer buffer ("PL_parser->linestr"),
immediately after the current lexing point
("PL_parser->bufptr"), reallocating the buffer if necessary.
This means that lexing code that runs later will see the characters as if
they had appeared in the input. It is not recommended to do this as part
of normal parsing, and most uses of this facility run the risk of the
inserted characters being interpreted in an unintended manner.
The string to be inserted is represented by len octets starting at
pv. These octets are interpreted as either UTF-8 or Latin-1,
according to whether the "LEX_STUFF_UTF8" flag is set in
flags. The characters are recoded for the lexer buffer, according
to how the buffer is currently being interpreted
("lex_bufutf8"). If a string to be inserted is available as a
Perl scalar, the "lex_stuff_sv" function is more convenient.
void lex_stuff_pvn(const char *pv, STRLEN len,
U32 flags)
- lex_stuff_pvs
- NOTE: this function is experimental and may change or be removed without
notice.
Like "lex_stuff_pvn", but takes a literal string instead of a
string/length pair.
void lex_stuff_pvs(const char *pv, U32 flags)
- lex_stuff_sv
- NOTE: this function is experimental and may change or be removed without
notice.
Insert characters into the lexer buffer ("PL_parser->linestr"),
immediately after the current lexing point
("PL_parser->bufptr"), reallocating the buffer if necessary.
This means that lexing code that runs later will see the characters as if
they had appeared in the input. It is not recommended to do this as part
of normal parsing, and most uses of this facility run the risk of the
inserted characters being interpreted in an unintended manner.
The string to be inserted is the string value of sv. The characters
are recoded for the lexer buffer, according to how the buffer is currently
being interpreted ("lex_bufutf8"). If a string to be inserted is
not already a Perl scalar, the "lex_stuff_pvn" function avoids
the need to construct a scalar.
void lex_stuff_sv(SV *sv, U32 flags)
- lex_unstuff
- NOTE: this function is experimental and may change or be removed without
notice.
Discards text about to be lexed, from "PL_parser->bufptr" up to
ptr. Text following ptr will be moved, and the buffer
shortened. This hides the discarded text from any lexing code that runs
later, as if the text had never appeared.
This is not the normal way to consume lexed text. For that, use
"lex_read_to".
void lex_unstuff(char *ptr)
- parse_arithexpr
- NOTE: this function is experimental and may change or be removed without
notice.
Parse a Perl arithmetic expression. This may contain operators of precedence
down to the bit shift operators. The expression must be followed (and thus
terminated) either by a comparison or lower-precedence operator or by
something that would normally terminate an expression such as semicolon.
If flags includes "PARSE_OPTIONAL" then the expression is
optional, otherwise it is mandatory. It is up to the caller to ensure that
the dynamic parser state ("PL_parser" et al) is correctly set to
reflect the source of the code to be parsed and the lexical context for
the expression.
The op tree representing the expression is returned. If an optional
expression is absent, a null pointer is returned, otherwise the pointer
will be non-null.
If an error occurs in parsing or compilation, in most cases a valid op tree
is returned anyway. The error is reflected in the parser state, normally
resulting in a single exception at the top level of parsing which covers
all the compilation errors that occurred. Some compilation errors,
however, will throw an exception immediately.
OP * parse_arithexpr(U32 flags)
- parse_barestmt
- NOTE: this function is experimental and may change or be removed without
notice.
Parse a single unadorned Perl statement. This may be a normal imperative
statement or a declaration that has compile-time effect. It does not
include any label or other affixture. It is up to the caller to ensure
that the dynamic parser state ("PL_parser" et al) is correctly
set to reflect the source of the code to be parsed and the lexical context
for the statement.
The op tree representing the statement is returned. This may be a null
pointer if the statement is null, for example if it was actually a
subroutine definition (which has compile-time side effects). If not null,
it will be ops directly implementing the statement, suitable to pass to
"newSTATEOP". It will not normally include a
"nextstate" or equivalent op (except for those embedded in a
scope contained entirely within the statement).
If an error occurs in parsing or compilation, in most cases a valid op tree
(most likely null) is returned anyway. The error is reflected in the
parser state, normally resulting in a single exception at the top level of
parsing which covers all the compilation errors that occurred. Some
compilation errors, however, will throw an exception immediately.
The flags parameter is reserved for future use, and must always be
zero.
OP * parse_barestmt(U32 flags)
- parse_block
- NOTE: this function is experimental and may change or be removed without
notice.
Parse a single complete Perl code block. This consists of an opening brace,
a sequence of statements, and a closing brace. The block constitutes a
lexical scope, so "my" variables and various compile-time
effects can be contained within it. It is up to the caller to ensure that
the dynamic parser state ("PL_parser" et al) is correctly set to
reflect the source of the code to be parsed and the lexical context for
the statement.
The op tree representing the code block is returned. This is always a real
op, never a null pointer. It will normally be a "lineseq" list,
including "nextstate" or equivalent ops. No ops to construct any
kind of runtime scope are included by virtue of it being a block.
If an error occurs in parsing or compilation, in most cases a valid op tree
(most likely null) is returned anyway. The error is reflected in the
parser state, normally resulting in a single exception at the top level of
parsing which covers all the compilation errors that occurred. Some
compilation errors, however, will throw an exception immediately.
The flags parameter is reserved for future use, and must always be
zero.
OP * parse_block(U32 flags)
- parse_fullexpr
- NOTE: this function is experimental and may change or be removed without
notice.
Parse a single complete Perl expression. This allows the full expression
grammar, including the lowest-precedence operators such as "or".
The expression must be followed (and thus terminated) by a token that an
expression would normally be terminated by: end-of-file, closing
bracketing punctuation, semicolon, or one of the keywords that signals a
postfix expression-statement modifier. If flags includes
"PARSE_OPTIONAL" then the expression is optional, otherwise it
is mandatory. It is up to the caller to ensure that the dynamic parser
state ("PL_parser" et al) is correctly set to reflect the source
of the code to be parsed and the lexical context for the expression.
The op tree representing the expression is returned. If an optional
expression is absent, a null pointer is returned, otherwise the pointer
will be non-null.
If an error occurs in parsing or compilation, in most cases a valid op tree
is returned anyway. The error is reflected in the parser state, normally
resulting in a single exception at the top level of parsing which covers
all the compilation errors that occurred. Some compilation errors,
however, will throw an exception immediately.
OP * parse_fullexpr(U32 flags)
- parse_fullstmt
- NOTE: this function is experimental and may change or be removed without
notice.
Parse a single complete Perl statement. This may be a normal imperative
statement or a declaration that has compile-time effect, and may include
optional labels. It is up to the caller to ensure that the dynamic parser
state ("PL_parser" et al) is correctly set to reflect the source
of the code to be parsed and the lexical context for the statement.
The op tree representing the statement is returned. This may be a null
pointer if the statement is null, for example if it was actually a
subroutine definition (which has compile-time side effects). If not null,
it will be the result of a "newSTATEOP" call, normally including
a "nextstate" or equivalent op.
If an error occurs in parsing or compilation, in most cases a valid op tree
(most likely null) is returned anyway. The error is reflected in the
parser state, normally resulting in a single exception at the top level of
parsing which covers all the compilation errors that occurred. Some
compilation errors, however, will throw an exception immediately.
The flags parameter is reserved for future use, and must always be
zero.
OP * parse_fullstmt(U32 flags)
- parse_label
- NOTE: this function is experimental and may change or be removed without
notice.
Parse a single label, possibly optional, of the type that may prefix a Perl
statement. It is up to the caller to ensure that the dynamic parser state
("PL_parser" et al) is correctly set to reflect the source of
the code to be parsed. If flags includes "PARSE_OPTIONAL"
then the label is optional, otherwise it is mandatory.
The name of the label is returned in the form of a fresh scalar. If an
optional label is absent, a null pointer is returned.
If an error occurs in parsing, which can only occur if the label is
mandatory, a valid label is returned anyway. The error is reflected in the
parser state, normally resulting in a single exception at the top level of
parsing which covers all the compilation errors that occurred.
SV * parse_label(U32 flags)
- parse_listexpr
- NOTE: this function is experimental and may change or be removed without
notice.
Parse a Perl list expression. This may contain operators of precedence down
to the comma operator. The expression must be followed (and thus
terminated) either by a low-precedence logic operator such as
"or" or by something that would normally terminate an expression
such as semicolon. If flags includes "PARSE_OPTIONAL"
then the expression is optional, otherwise it is mandatory. It is up to
the caller to ensure that the dynamic parser state ("PL_parser"
et al) is correctly set to reflect the source of the code to be parsed and
the lexical context for the expression.
The op tree representing the expression is returned. If an optional
expression is absent, a null pointer is returned, otherwise the pointer
will be non-null.
If an error occurs in parsing or compilation, in most cases a valid op tree
is returned anyway. The error is reflected in the parser state, normally
resulting in a single exception at the top level of parsing which covers
all the compilation errors that occurred. Some compilation errors,
however, will throw an exception immediately.
OP * parse_listexpr(U32 flags)
- parse_stmtseq
- NOTE: this function is experimental and may change or be removed without
notice.
Parse a sequence of zero or more Perl statements. These may be normal
imperative statements, including optional labels, or declarations that
have compile-time effect, or any mixture thereof. The statement sequence
ends when a closing brace or end-of-file is encountered in a place where a
new statement could have validly started. It is up to the caller to ensure
that the dynamic parser state ("PL_parser" et al) is correctly
set to reflect the source of the code to be parsed and the lexical context
for the statements.
The op tree representing the statement sequence is returned. This may be a
null pointer if the statements were all null, for example if there were no
statements or if there were only subroutine definitions (which have
compile-time side effects). If not null, it will be a "lineseq"
list, normally including "nextstate" or equivalent ops.
If an error occurs in parsing or compilation, in most cases a valid op tree
is returned anyway. The error is reflected in the parser state, normally
resulting in a single exception at the top level of parsing which covers
all the compilation errors that occurred. Some compilation errors,
however, will throw an exception immediately.
The flags parameter is reserved for future use, and must always be
zero.
OP * parse_stmtseq(U32 flags)
- parse_termexpr
- NOTE: this function is experimental and may change or be removed without
notice.
Parse a Perl term expression. This may contain operators of precedence down
to the assignment operators. The expression must be followed (and thus
terminated) either by a comma or lower-precedence operator or by something
that would normally terminate an expression such as semicolon. If
flags includes "PARSE_OPTIONAL" then the expression is
optional, otherwise it is mandatory. It is up to the caller to ensure that
the dynamic parser state ("PL_parser" et al) is correctly set to
reflect the source of the code to be parsed and the lexical context for
the expression.
The op tree representing the expression is returned. If an optional
expression is absent, a null pointer is returned, otherwise the pointer
will be non-null.
If an error occurs in parsing or compilation, in most cases a valid op tree
is returned anyway. The error is reflected in the parser state, normally
resulting in a single exception at the top level of parsing which covers
all the compilation errors that occurred. Some compilation errors,
however, will throw an exception immediately.
OP * parse_termexpr(U32 flags)
- PL_parser
- Pointer to a structure encapsulating the state of the parsing operation
currently in progress. The pointer can be locally changed to perform a
nested parse without interfering with the state of an outer parse.
Individual members of "PL_parser" have their own
documentation.
- PL_parser->bufend
- NOTE: this function is experimental and may change or be removed without
notice.
Direct pointer to the end of the chunk of text currently being lexed, the
end of the lexer buffer. This is equal to
"SvPVX(PL_parser->linestr) + SvCUR(PL_parser->linestr)". A
"NUL" character (zero octet) is always located at the end of the
buffer, and does not count as part of the buffer's contents.
- PL_parser->bufptr
- NOTE: this function is experimental and may change or be removed without
notice.
Points to the current position of lexing inside the lexer buffer. Characters
around this point may be freely examined, within the range delimited by
"SvPVX("PL_parser->linestr")" and
"PL_parser->bufend". The octets of the buffer may be intended
to be interpreted as either UTF-8 or Latin-1, as indicated by
"lex_bufutf8".
Lexing code (whether in the Perl core or not) moves this pointer past the
characters that it consumes. It is also expected to perform some
bookkeeping whenever a newline character is consumed. This movement can be
more conveniently performed by the function "lex_read_to", which
handles newlines appropriately.
Interpretation of the buffer's octets can be abstracted out by using the
slightly higher-level functions "lex_peek_unichar" and
"lex_read_unichar".
- PL_parser->linestart
- NOTE: this function is experimental and may change or be removed without
notice.
Points to the start of the current line inside the lexer buffer. This is
useful for indicating at which column an error occurred, and not much
else. This must be updated by any lexing code that consumes a newline; the
function "lex_read_to" handles this detail.
- PL_parser->linestr
- NOTE: this function is experimental and may change or be removed without
notice.
Buffer scalar containing the chunk currently under consideration of the text
currently being lexed. This is always a plain string scalar (for which
"SvPOK" is true). It is not intended to be used as a scalar by
normal scalar means; instead refer to the buffer directly by the pointer
variables described below.
The lexer maintains various "char*" pointers to things in the
"PL_parser->linestr" buffer. If
"PL_parser->linestr" is ever reallocated, all of these
pointers must be updated. Don't attempt to do this manually, but rather
use "lex_grow_linestr" if you need to reallocate the buffer.
The content of the text chunk in the buffer is commonly exactly one complete
line of input, up to and including a newline terminator, but there are
situations where it is otherwise. The octets of the buffer may be intended
to be interpreted as either UTF-8 or Latin-1. The function
"lex_bufutf8" tells you which. Do not use the "SvUTF8"
flag on this scalar, which may disagree with it.
For direct examination of the buffer, the variable
"PL_parser->bufend" points to the end of the buffer. The
current lexing position is pointed to by "PL_parser->bufptr".
Direct use of these pointers is usually preferable to examination of the
scalar through normal scalar means.
- sync_locale
- Changing the program's locale should be avoided by XS code. Nevertheless,
certain non-Perl libraries called from XS, such as "Gtk" do so.
When this happens, Perl needs to be told that the locale has changed. Use
this macro to do so, before returning to Perl code.
void sync_locale()
Magical Functions¶
- mg_clear
- Clear something magical that the SV represents. See "sv_magic".
int mg_clear(SV* sv)
- mg_copy
- Copies the magic from one SV to another. See "sv_magic".
int mg_copy(SV *sv, SV *nsv, const char *key,
I32 klen)
- mg_find
- Finds the magic pointer for type matching the SV. See
"sv_magic".
MAGIC* mg_find(const SV* sv, int type)
- mg_findext
- Finds the magic pointer of "type" with the given
"vtbl" for the "SV". See "sv_magicext".
MAGIC* mg_findext(const SV* sv, int type,
const MGVTBL *vtbl)
- mg_free
- Free any magic storage used by the SV. See "sv_magic".
int mg_free(SV* sv)
- mg_free_type
- Remove any magic of type how from the SV sv. See
"sv_magic".
void mg_free_type(SV *sv, int how)
- mg_get
- Do magic before a value is retrieved from the SV. The type of SV must be
>= SVt_PVMG. See "sv_magic".
int mg_get(SV* sv)
- mg_length
- DEPRECATED! It is planned to remove this function from a future release of
Perl. Do not use it for new code; remove it from existing code.
Reports on the SV's length in bytes, calling length magic if available, but
does not set the UTF8 flag on the sv. It will fall back to 'get' magic if
there is no 'length' magic, but with no indication as to whether it called
'get' magic. It assumes the sv is a PVMG or higher. Use sv_len()
instead.
U32 mg_length(SV* sv)
- mg_magical
- Turns on the magical status of an SV. See "sv_magic".
void mg_magical(SV* sv)
- mg_set
- Do magic after a value is assigned to the SV. See "sv_magic".
int mg_set(SV* sv)
- SvGETMAGIC
- Invokes "mg_get" on an SV if it has 'get' magic. For example,
this will call "FETCH" on a tied variable. This macro evaluates
its argument more than once.
void SvGETMAGIC(SV* sv)
- SvLOCK
- Arranges for a mutual exclusion lock to be obtained on sv if a suitable
module has been loaded.
void SvLOCK(SV* sv)
- SvSETMAGIC
- Invokes "mg_set" on an SV if it has 'set' magic. This is
necessary after modifying a scalar, in case it is a magical variable like
$| or a tied variable (it calls "STORE"). This macro evaluates
its argument more than once.
void SvSETMAGIC(SV* sv)
- SvSetMagicSV
- Like "SvSetSV", but does any set magic required afterwards.
void SvSetMagicSV(SV* dsv, SV* ssv)
- SvSetMagicSV_nosteal
- Like "SvSetSV_nosteal", but does any set magic required
afterwards.
void SvSetMagicSV_nosteal(SV* dsv, SV* ssv)
- SvSetSV
- Calls "sv_setsv" if dsv is not the same as ssv. May evaluate
arguments more than once. Does not handle 'set' magic on the destination
SV.
void SvSetSV(SV* dsv, SV* ssv)
- SvSetSV_nosteal
- Calls a non-destructive version of "sv_setsv" if dsv is not the
same as ssv. May evaluate arguments more than once.
void SvSetSV_nosteal(SV* dsv, SV* ssv)
- SvSHARE
- Arranges for sv to be shared between threads if a suitable module has been
loaded.
void SvSHARE(SV* sv)
- SvUNLOCK
- Releases a mutual exclusion lock on sv if a suitable module has been
loaded.
void SvUNLOCK(SV* sv)
Memory Management¶
- Copy
- The XSUB-writer's interface to the C "memcpy" function. The
"src" is the source, "dest" is the destination,
"nitems" is the number of items, and "type" is the
type. May fail on overlapping copies. See also "Move".
void Copy(void* src, void* dest, int nitems, type)
- CopyD
- Like "Copy" but returns dest. Useful for encouraging compilers
to tail-call optimise.
void * CopyD(void* src, void* dest, int nitems, type)
- Move
- The XSUB-writer's interface to the C "memmove" function. The
"src" is the source, "dest" is the destination,
"nitems" is the number of items, and "type" is the
type. Can do overlapping moves. See also "Copy".
void Move(void* src, void* dest, int nitems, type)
- MoveD
- Like "Move" but returns dest. Useful for encouraging compilers
to tail-call optimise.
void * MoveD(void* src, void* dest, int nitems, type)
- Newx
- The XSUB-writer's interface to the C "malloc" function.
Memory obtained by this should ONLY be freed with
"Safefree".
In 5.9.3, Newx() and friends replace the older New() API, and
drops the first parameter, x, a debug aid which allowed callers to
identify themselves. This aid has been superseded by a new build option,
PERL_MEM_LOG (see "PERL_MEM_LOG" in perlhacktips). The older API
is still there for use in XS modules supporting older perls.
void Newx(void* ptr, int nitems, type)
- Newxc
- The XSUB-writer's interface to the C "malloc" function, with
cast. See also "Newx".
Memory obtained by this should ONLY be freed with
"Safefree".
void Newxc(void* ptr, int nitems, type, cast)
- Newxz
- The XSUB-writer's interface to the C "malloc" function. The
allocated memory is zeroed with "memzero". See also
"Newx".
Memory obtained by this should ONLY be freed with
"Safefree".
void Newxz(void* ptr, int nitems, type)
- Poison
- PoisonWith(0xEF) for catching access to freed memory.
void Poison(void* dest, int nitems, type)
- PoisonFree
- PoisonWith(0xEF) for catching access to freed memory.
void PoisonFree(void* dest, int nitems, type)
- PoisonNew
- PoisonWith(0xAB) for catching access to allocated but uninitialized
memory.
void PoisonNew(void* dest, int nitems, type)
- PoisonWith
- Fill up memory with a byte pattern (a byte repeated over and over again)
that hopefully catches attempts to access uninitialized memory.
void PoisonWith(void* dest, int nitems, type,
U8 byte)
- Renew
- The XSUB-writer's interface to the C "realloc" function.
Memory obtained by this should ONLY be freed with
"Safefree".
void Renew(void* ptr, int nitems, type)
- Renewc
- The XSUB-writer's interface to the C "realloc" function, with
cast.
Memory obtained by this should ONLY be freed with
"Safefree".
void Renewc(void* ptr, int nitems, type, cast)
- Safefree
- The XSUB-writer's interface to the C "free" function.
This should ONLY be used on memory obtained using "Newx"
and friends.
void Safefree(void* ptr)
- savepv
- Perl's version of "strdup()". Returns a pointer to a newly
allocated string which is a duplicate of "pv". The size of the
string is determined by "strlen()", which means it may not
contain embedded "NUL" characters and must have a trailing
"NUL". The memory allocated for the new string can be freed with
the "Safefree()" function.
On some platforms, Windows for example, all allocated memory owned by a
thread is deallocated when that thread ends. So if you need that not to
happen, you need to use the shared memory functions, such as
"savesharedpv".
char* savepv(const char* pv)
- savepvn
- Perl's version of what "strndup()" would be if it existed.
Returns a pointer to a newly allocated string which is a duplicate of the
first "len" bytes from "pv", plus a trailing
"NUL" byte. The memory allocated for the new string can be freed
with the "Safefree()" function.
On some platforms, Windows for example, all allocated memory owned by a
thread is deallocated when that thread ends. So if you need that not to
happen, you need to use the shared memory functions, such as
"savesharedpvn".
char* savepvn(const char* pv, I32 len)
- savepvs
- Like "savepvn", but takes a literal "NUL"-terminated
string instead of a string/length pair.
char* savepvs(const char* s)
- savesharedpv
- A version of "savepv()" which allocates the duplicate string in
memory which is shared between threads.
char* savesharedpv(const char* pv)
- savesharedpvn
- A version of "savepvn()" which allocates the duplicate string in
memory which is shared between threads. (With the specific difference that
a NULL pointer is not acceptable)
char* savesharedpvn(const char *const pv,
const STRLEN len)
- savesharedpvs
- A version of "savepvs()" which allocates the duplicate string in
memory which is shared between threads.
char* savesharedpvs(const char* s)
- savesharedsvpv
- A version of "savesharedpv()" which allocates the duplicate
string in memory which is shared between threads.
char* savesharedsvpv(SV *sv)
- savesvpv
- A version of "savepv()"/"savepvn()" which gets the
string to duplicate from the passed in SV using "SvPV()"
On some platforms, Windows for example, all allocated memory owned by a
thread is deallocated when that thread ends. So if you need that not to
happen, you need to use the shared memory functions, such as
"savesharedsvpv".
char* savesvpv(SV* sv)
- StructCopy
- This is an architecture-independent macro to copy one structure to
another.
void StructCopy(type *src, type *dest, type)
- Zero
- The XSUB-writer's interface to the C "memzero" function. The
"dest" is the destination, "nitems" is the number of
items, and "type" is the type.
void Zero(void* dest, int nitems, type)
- ZeroD
- Like "Zero" but returns dest. Useful for encouraging compilers
to tail-call optimise.
void * ZeroD(void* dest, int nitems, type)
Miscellaneous Functions¶
- fbm_compile
- Analyses the string in order to make fast searches on it using
fbm_instr() -- the Boyer-Moore algorithm.
void fbm_compile(SV* sv, U32 flags)
- fbm_instr
- Returns the location of the SV in the string delimited by "big"
and "bigend". It returns "NULL" if the string can't be
found. The "sv" does not have to be fbm_compiled, but the search
will not be as fast then.
char* fbm_instr(unsigned char* big,
unsigned char* bigend, SV* littlestr,
U32 flags)
- foldEQ
- Returns true if the leading len bytes of the strings s1 and s2 are the
same case-insensitively; false otherwise. Uppercase and lowercase ASCII
range bytes match themselves and their opposite case counterparts.
Non-cased and non-ASCII range bytes match only themselves.
I32 foldEQ(const char* a, const char* b, I32 len)
- foldEQ_locale
- Returns true if the leading len bytes of the strings s1 and s2 are the
same case-insensitively in the current locale; false otherwise.
I32 foldEQ_locale(const char* a, const char* b,
I32 len)
- form
- Takes a sprintf-style format pattern and conventional (non-SV) arguments
and returns the formatted string.
(char *) Perl_form(pTHX_ const char* pat, ...)
can be used any place a string (char *) is required:
char * s = Perl_form("%d.%d",major,minor);
Uses a single private buffer so if you want to format several strings you
must explicitly copy the earlier strings away (and free the copies when
you are done).
char* form(const char* pat, ...)
- getcwd_sv
- Fill the sv with current working directory
int getcwd_sv(SV* sv)
- mess
- Take a sprintf-style format pattern and argument list. These are used to
generate a string message. If the message does not end with a newline,
then it will be extended with some indication of the current location in
the code, as described for "mess_sv".
Normally, the resulting message is returned in a new mortal SV. During
global destruction a single SV may be shared between uses of this
function.
SV * mess(const char *pat, ...)
- mess_sv
- Expands a message, intended for the user, to include an indication of the
current location in the code, if the message does not already appear to be
complete.
"basemsg" is the initial message or object. If it is a reference,
it will be used as-is and will be the result of this function. Otherwise
it is used as a string, and if it already ends with a newline, it is taken
to be complete, and the result of this function will be the same string.
If the message does not end with a newline, then a segment such as
"at foo.pl line 37" will be appended, and possibly other clauses
indicating the current state of execution. The resulting message will end
with a dot and a newline.
Normally, the resulting message is returned in a new mortal SV. During
global destruction a single SV may be shared between uses of this
function. If "consume" is true, then the function is permitted
(but not required) to modify and return "basemsg" instead of
allocating a new SV.
SV * mess_sv(SV *basemsg, bool consume)
- my_snprintf
- The C library "snprintf" functionality, if available and
standards-compliant (uses "vsnprintf", actually). However, if
the "vsnprintf" is not available, will unfortunately use the
unsafe "vsprintf" which can overrun the buffer (there is an
overrun check, but that may be too late). Consider using
"sv_vcatpvf" instead, or getting "vsnprintf".
int my_snprintf(char *buffer, const Size_t len,
const char *format, ...)
- my_sprintf
- The C library "sprintf", wrapped if necessary, to ensure that it
will return the length of the string written to the buffer. Only rare
pre-ANSI systems need the wrapper function - usually this is a direct call
to "sprintf".
int my_sprintf(char *buffer, const char *pat, ...)
- my_strlcat
- The C library "strlcat" if available, or a Perl implementation
of it. This operates on C "NUL"-terminated strings.
"my_strlcat()" appends string "src" to the end of
"dst". It will append at most
"size - strlen(dst) - 1" characters.
It will then "NUL"-terminate, unless "size" is 0 or
the original "dst" string was longer than "size" (in
practice this should not happen as it means that either "size"
is incorrect or that "dst" is not a proper
"NUL"-terminated string).
Note that "size" is the full size of the destination buffer and
the result is guaranteed to be "NUL"-terminated if there is
room. Note that room for the "NUL" should be included in
"size".
Size_t my_strlcat(char *dst, const char *src,
Size_t size)
- my_strlcpy
- The C library "strlcpy" if available, or a Perl implementation
of it. This operates on C "NUL"-terminated strings.
"my_strlcpy()" copies up to "size - 1"
characters from the string "src" to "dst",
"NUL"-terminating the result if "size" is not 0.
Size_t my_strlcpy(char *dst, const char *src,
Size_t size)
- my_vsnprintf
- The C library "vsnprintf" if available and standards-compliant.
However, if if the "vsnprintf" is not available, will
unfortunately use the unsafe "vsprintf" which can overrun the
buffer (there is an overrun check, but that may be too late). Consider
using "sv_vcatpvf" instead, or getting "vsnprintf".
int my_vsnprintf(char *buffer, const Size_t len,
const char *format, va_list ap)
- READ_XDIGIT
- Returns the value of an ASCII-range hex digit and advances the string
pointer. Behaviour is only well defined when isXDIGIT(*str) is true.
U8 READ_XDIGIT(char str*)
- strEQ
- Test two strings to see if they are equal. Returns true or false.
bool strEQ(char* s1, char* s2)
- strGE
- Test two strings to see if the first, "s1", is greater than or
equal to the second, "s2". Returns true or false.
bool strGE(char* s1, char* s2)
- strGT
- Test two strings to see if the first, "s1", is greater than the
second, "s2". Returns true or false.
bool strGT(char* s1, char* s2)
- strLE
- Test two strings to see if the first, "s1", is less than or
equal to the second, "s2". Returns true or false.
bool strLE(char* s1, char* s2)
- strLT
- Test two strings to see if the first, "s1", is less than the
second, "s2". Returns true or false.
bool strLT(char* s1, char* s2)
- strNE
- Test two strings to see if they are different. Returns true or false.
bool strNE(char* s1, char* s2)
- strnEQ
- Test two strings to see if they are equal. The "len" parameter
indicates the number of bytes to compare. Returns true or false. (A
wrapper for "strncmp").
bool strnEQ(char* s1, char* s2, STRLEN len)
- strnNE
- Test two strings to see if they are different. The "len"
parameter indicates the number of bytes to compare. Returns true or false.
(A wrapper for "strncmp").
bool strnNE(char* s1, char* s2, STRLEN len)
- sv_destroyable
- Dummy routine which reports that object can be destroyed when there is no
sharing module present. It ignores its single SV argument, and returns
'true'. Exists to avoid test for a NULL function pointer and because it
could potentially warn under some level of strict-ness.
bool sv_destroyable(SV *sv)
- sv_nosharing
- Dummy routine which "shares" an SV when there is no sharing
module present. Or "locks" it. Or "unlocks" it. In
other words, ignores its single SV argument. Exists to avoid test for a
NULL function pointer and because it could potentially warn under some
level of strict-ness.
void sv_nosharing(SV *sv)
- vmess
- "pat" and "args" are a sprintf-style format pattern
and encapsulated argument list. These are used to generate a string
message. If the message does not end with a newline, then it will be
extended with some indication of the current location in the code, as
described for "mess_sv".
Normally, the resulting message is returned in a new mortal SV. During
global destruction a single SV may be shared between uses of this
function.
SV * vmess(const char *pat, va_list *args)
MRO Functions¶
- mro_get_linear_isa
- Returns the mro linearisation for the given stash. By default, this will
be whatever "mro_get_linear_isa_dfs" returns unless some other
MRO is in effect for the stash. The return value is a read-only AV*.
You are responsible for "SvREFCNT_inc()" on the return value if
you plan to store it anywhere semi-permanently (otherwise it might be
deleted out from under you the next time the cache is invalidated).
AV* mro_get_linear_isa(HV* stash)
- mro_method_changed_in
- Invalidates method caching on any child classes of the given stash, so
that they might notice the changes in this one.
Ideally, all instances of "PL_sub_generation++" in perl source
outside of mro.c should be replaced by calls to this.
Perl automatically handles most of the common ways a method might be
redefined. However, there are a few ways you could change a method in a
stash without the cache code noticing, in which case you need to call this
method afterwards:
1) Directly manipulating the stash HV entries from XS code.
2) Assigning a reference to a readonly scalar constant into a stash entry in
order to create a constant subroutine (like constant.pm does).
This same method is available from pure perl via,
"mro::method_changed_in(classname)".
void mro_method_changed_in(HV* stash)
- mro_register
- Registers a custom mro plugin. See perlmroapi for details.
void mro_register(const struct mro_alg *mro)
Multicall Functions¶
- dMULTICALL
- Declare local variables for a multicall. See "LIGHTWEIGHT
CALLBACKS" in perlcall.
dMULTICALL;
- MULTICALL
- Make a lightweight callback. See "LIGHTWEIGHT CALLBACKS" in
perlcall.
MULTICALL;
- POP_MULTICALL
- Closing bracket for a lightweight callback. See "LIGHTWEIGHT
CALLBACKS" in perlcall.
POP_MULTICALL;
- PUSH_MULTICALL
- Opening bracket for a lightweight callback. See "LIGHTWEIGHT
CALLBACKS" in perlcall.
PUSH_MULTICALL;
Numeric functions¶
- grok_bin
- converts a string representing a binary number to numeric form.
On entry start and *len give the string to scan, *flags
gives conversion flags, and result should be NULL or a pointer to
an NV. The scan stops at the end of the string, or the first invalid
character. Unless "PERL_SCAN_SILENT_ILLDIGIT" is set in
*flags, encountering an invalid character will also trigger a
warning. On return *len is set to the length of the scanned string,
and *flags gives output flags.
If the value is <= "UV_MAX" it is returned as a UV, the output
flags are clear, and nothing is written to *result. If the value is
> UV_MAX "grok_bin" returns UV_MAX, sets
"PERL_SCAN_GREATER_THAN_UV_MAX" in the output flags, and writes
the value to *result (or the value is discarded if result is
NULL).
The binary number may optionally be prefixed with "0b" or
"b" unless "PERL_SCAN_DISALLOW_PREFIX" is set in
*flags on entry. If "PERL_SCAN_ALLOW_UNDERSCORES" is set
in *flags then the binary number may use '_' characters to separate
digits.
UV grok_bin(const char* start, STRLEN* len_p,
I32* flags, NV *result)
- grok_hex
- converts a string representing a hex number to numeric form.
On entry start and *len_p give the string to scan,
*flags gives conversion flags, and result should be NULL or
a pointer to an NV. The scan stops at the end of the string, or the first
invalid character. Unless "PERL_SCAN_SILENT_ILLDIGIT" is set in
*flags, encountering an invalid character will also trigger a
warning. On return *len is set to the length of the scanned string,
and *flags gives output flags.
If the value is <= UV_MAX it is returned as a UV, the output flags are
clear, and nothing is written to *result. If the value is >
UV_MAX "grok_hex" returns UV_MAX, sets
"PERL_SCAN_GREATER_THAN_UV_MAX" in the output flags, and writes
the value to *result (or the value is discarded if result is
NULL).
The hex number may optionally be prefixed with "0x" or
"x" unless "PERL_SCAN_DISALLOW_PREFIX" is set in
*flags on entry. If "PERL_SCAN_ALLOW_UNDERSCORES" is set
in *flags then the hex number may use '_' characters to separate
digits.
UV grok_hex(const char* start, STRLEN* len_p,
I32* flags, NV *result)
- grok_number
- Recognise (or not) a number. The type of the number is returned (0 if
unrecognised), otherwise it is a bit-ORed combination of IS_NUMBER_IN_UV,
IS_NUMBER_GREATER_THAN_UV_MAX, IS_NUMBER_NOT_INT, IS_NUMBER_NEG,
IS_NUMBER_INFINITY, IS_NUMBER_NAN (defined in perl.h).
If the value of the number can fit in a UV, it is returned in the *valuep
IS_NUMBER_IN_UV will be set to indicate that *valuep is valid,
IS_NUMBER_IN_UV will never be set unless *valuep is valid, but *valuep may
have been assigned to during processing even though IS_NUMBER_IN_UV is not
set on return. If valuep is NULL, IS_NUMBER_IN_UV will be set for the same
cases as when valuep is non-NULL, but no actual assignment (or SEGV) will
occur.
IS_NUMBER_NOT_INT will be set with IS_NUMBER_IN_UV if trailing decimals were
seen (in which case *valuep gives the true value truncated to an integer),
and IS_NUMBER_NEG if the number is negative (in which case *valuep holds
the absolute value). IS_NUMBER_IN_UV is not set if e notation was used or
the number is larger than a UV.
int grok_number(const char *pv, STRLEN len,
UV *valuep)
- grok_numeric_radix
- Scan and skip for a numeric decimal separator (radix).
bool grok_numeric_radix(const char **sp,
const char *send)
- grok_oct
- converts a string representing an octal number to numeric form.
On entry start and *len give the string to scan, *flags
gives conversion flags, and result should be NULL or a pointer to
an NV. The scan stops at the end of the string, or the first invalid
character. Unless "PERL_SCAN_SILENT_ILLDIGIT" is set in
*flags, encountering an 8 or 9 will also trigger a warning. On
return *len is set to the length of the scanned string, and
*flags gives output flags.
If the value is <= UV_MAX it is returned as a UV, the output flags are
clear, and nothing is written to *result. If the value is >
UV_MAX "grok_oct" returns UV_MAX, sets
"PERL_SCAN_GREATER_THAN_UV_MAX" in the output flags, and writes
the value to *result (or the value is discarded if result is
NULL).
If "PERL_SCAN_ALLOW_UNDERSCORES" is set in *flags then the
octal number may use '_' characters to separate digits.
UV grok_oct(const char* start, STRLEN* len_p,
I32* flags, NV *result)
- Perl_signbit
- NOTE: this function is experimental and may change or be removed without
notice.
Return a non-zero integer if the sign bit on an NV is set, and 0 if it is
not.
If Configure detects this system has a signbit() that will work with
our NVs, then we just use it via the #define in perl.h. Otherwise, fall
back on this implementation. As a first pass, this gets everything right
except -0.0. Alas, catching -0.0 is the main use for this function, so
this is not too helpful yet. Still, at least we have the scaffolding in
place to support other systems, should that prove useful.
Configure notes: This function is called 'Perl_signbit' instead of a plain
'signbit' because it is easy to imagine a system having a signbit()
function or macro that doesn't happen to work with our particular choice
of NVs. We shouldn't just re-#define signbit as Perl_signbit and expect
the standard system headers to be happy. Also, this is a no-context
function (no pTHX_) because Perl_signbit() is usually re-#defined
in perl.h as a simple macro call to the system's signbit(). Users
should just always call Perl_signbit().
int Perl_signbit(NV f)
- scan_bin
- For backwards compatibility. Use "grok_bin" instead.
NV scan_bin(const char* start, STRLEN len,
STRLEN* retlen)
- scan_hex
- For backwards compatibility. Use "grok_hex" instead.
NV scan_hex(const char* start, STRLEN len,
STRLEN* retlen)
- scan_oct
- For backwards compatibility. Use "grok_oct" instead.
NV scan_oct(const char* start, STRLEN len,
STRLEN* retlen)
Optree construction¶
- newASSIGNOP
- Constructs, checks, and returns an assignment op. left and
right supply the parameters of the assignment; they are consumed by
this function and become part of the constructed op tree.
If optype is "OP_ANDASSIGN", "OP_ORASSIGN", or
"OP_DORASSIGN", then a suitable conditional optree is
constructed. If optype is the opcode of a binary operator, such as
"OP_BIT_OR", then an op is constructed that performs the binary
operation and assigns the result to the left argument. Either way, if
optype is non-zero then flags has no effect.
If optype is zero, then a plain scalar or list assignment is
constructed. Which type of assignment it is is automatically determined.
flags gives the eight bits of "op_flags", except that
"OPf_KIDS" will be set automatically, and, shifted up eight
bits, the eight bits of "op_private", except that the bit with
value 1 or 2 is automatically set as required.
OP * newASSIGNOP(I32 flags, OP *left, I32 optype,
OP *right)
- newBINOP
- Constructs, checks, and returns an op of any binary type. type is
the opcode. flags gives the eight bits of "op_flags",
except that "OPf_KIDS" will be set automatically, and, shifted
up eight bits, the eight bits of "op_private", except that the
bit with value 1 or 2 is automatically set as required. first and
last supply up to two ops to be the direct children of the binary
op; they are consumed by this function and become part of the constructed
op tree.
OP * newBINOP(I32 type, I32 flags, OP *first,
OP *last)
- newCONDOP
- Constructs, checks, and returns a conditional-expression
("cond_expr") op. flags gives the eight bits of
"op_flags", except that "OPf_KIDS" will be set
automatically, and, shifted up eight bits, the eight bits of
"op_private", except that the bit with value 1 is automatically
set. first supplies the expression selecting between the two
branches, and trueop and falseop supply the branches; they
are consumed by this function and become part of the constructed op tree.
OP * newCONDOP(I32 flags, OP *first, OP *trueop,
OP *falseop)
- newFOROP
- Constructs, checks, and returns an op tree expressing a
"foreach" loop (iteration through a list of values). This is a
heavyweight loop, with structure that allows exiting the loop by
"last" and suchlike.
sv optionally supplies the variable that will be aliased to each
item in turn; if null, it defaults to $_ (either lexical or global).
expr supplies the list of values to iterate over. block
supplies the main body of the loop, and cont optionally supplies a
"continue" block that operates as a second half of the body. All
of these optree inputs are consumed by this function and become part of
the constructed op tree.
flags gives the eight bits of "op_flags" for the
"leaveloop" op and, shifted up eight bits, the eight bits of
"op_private" for the "leaveloop" op, except that (in
both cases) some bits will be set automatically.
OP * newFOROP(I32 flags, OP *sv, OP *expr, OP *block,
OP *cont)
- newGIVENOP
- Constructs, checks, and returns an op tree expressing a "given"
block. cond supplies the expression that will be locally assigned
to a lexical variable, and block supplies the body of the
"given" construct; they are consumed by this function and become
part of the constructed op tree. defsv_off is the pad offset of the
scalar lexical variable that will be affected. If it is 0, the global $_
will be used.
OP * newGIVENOP(OP *cond, OP *block,
PADOFFSET defsv_off)
- newGVOP
- Constructs, checks, and returns an op of any type that involves an
embedded reference to a GV. type is the opcode. flags gives
the eight bits of "op_flags". gv identifies the GV that
the op should reference; calling this function does not transfer ownership
of any reference to it.
OP * newGVOP(I32 type, I32 flags, GV *gv)
- newLISTOP
- Constructs, checks, and returns an op of any list type. type is the
opcode. flags gives the eight bits of "op_flags", except
that "OPf_KIDS" will be set automatically if required.
first and last supply up to two ops to be direct children of
the list op; they are consumed by this function and become part of the
constructed op tree.
OP * newLISTOP(I32 type, I32 flags, OP *first,
OP *last)
- newLOGOP
- Constructs, checks, and returns a logical (flow control) op. type
is the opcode. flags gives the eight bits of "op_flags",
except that "OPf_KIDS" will be set automatically, and, shifted
up eight bits, the eight bits of "op_private", except that the
bit with value 1 is automatically set. first supplies the
expression controlling the flow, and other supplies the side
(alternate) chain of ops; they are consumed by this function and become
part of the constructed op tree.
OP * newLOGOP(I32 type, I32 flags, OP *first,
OP *other)
- newLOOPEX
- Constructs, checks, and returns a loop-exiting op (such as
"goto" or "last"). type is the opcode.
label supplies the parameter determining the target of the op; it
is consumed by this function and becomes part of the constructed op tree.
OP * newLOOPEX(I32 type, OP *label)
- newLOOPOP
- Constructs, checks, and returns an op tree expressing a loop. This is only
a loop in the control flow through the op tree; it does not have the
heavyweight loop structure that allows exiting the loop by
"last" and suchlike. flags gives the eight bits of
"op_flags" for the top-level op, except that some bits will be
set automatically as required. expr supplies the expression
controlling loop iteration, and block supplies the body of the
loop; they are consumed by this function and become part of the
constructed op tree. debuggable is currently unused and should
always be 1.
OP * newLOOPOP(I32 flags, I32 debuggable, OP *expr,
OP *block)
- newNULLLIST
- Constructs, checks, and returns a new "stub" op, which
represents an empty list expression.
OP * newNULLLIST()
- newOP
- Constructs, checks, and returns an op of any base type (any type that has
no extra fields). type is the opcode. flags gives the eight
bits of "op_flags", and, shifted up eight bits, the eight bits
of "op_private".
OP * newOP(I32 type, I32 flags)
- newPADOP
- Constructs, checks, and returns an op of any type that involves a
reference to a pad element. type is the opcode. flags gives
the eight bits of "op_flags". A pad slot is automatically
allocated, and is populated with sv; this function takes ownership
of one reference to it.
This function only exists if Perl has been compiled to use ithreads.
OP * newPADOP(I32 type, I32 flags, SV *sv)
- newPMOP
- Constructs, checks, and returns an op of any pattern matching type.
type is the opcode. flags gives the eight bits of
"op_flags" and, shifted up eight bits, the eight bits of
"op_private".
OP * newPMOP(I32 type, I32 flags)
- newPVOP
- Constructs, checks, and returns an op of any type that involves an
embedded C-level pointer (PV). type is the opcode. flags
gives the eight bits of "op_flags". pv supplies the
C-level pointer, which must have been allocated using
"PerlMemShared_malloc"; the memory will be freed when the op is
destroyed.
OP * newPVOP(I32 type, I32 flags, char *pv)
- newRANGE
- Constructs and returns a "range" op, with subordinate
"flip" and "flop" ops. flags gives the eight
bits of "op_flags" for the "flip" op and, shifted up
eight bits, the eight bits of "op_private" for both the
"flip" and "range" ops, except that the bit with value
1 is automatically set. left and right supply the
expressions controlling the endpoints of the range; they are consumed by
this function and become part of the constructed op tree.
OP * newRANGE(I32 flags, OP *left, OP *right)
- newSLICEOP
- Constructs, checks, and returns an "lslice" (list slice) op.
flags gives the eight bits of "op_flags", except that
"OPf_KIDS" will be set automatically, and, shifted up eight
bits, the eight bits of "op_private", except that the bit with
value 1 or 2 is automatically set as required. listval and
subscript supply the parameters of the slice; they are consumed by
this function and become part of the constructed op tree.
OP * newSLICEOP(I32 flags, OP *subscript,
OP *listval)
- newSTATEOP
- Constructs a state op (COP). The state op is normally a
"nextstate" op, but will be a "dbstate" op if
debugging is enabled for currently-compiled code. The state op is
populated from "PL_curcop" (or "PL_compiling"). If
label is non-null, it supplies the name of a label to attach to the
state op; this function takes ownership of the memory pointed at by
label, and will free it. flags gives the eight bits of
"op_flags" for the state op.
If o is null, the state op is returned. Otherwise the state op is
combined with o into a "lineseq" list op, which is
returned. o is consumed by this function and becomes part of the
returned op tree.
OP * newSTATEOP(I32 flags, char *label, OP *o)
- newSVOP
- Constructs, checks, and returns an op of any type that involves an
embedded SV. type is the opcode. flags gives the eight bits
of "op_flags". sv gives the SV to embed in the op; this
function takes ownership of one reference to it.
OP * newSVOP(I32 type, I32 flags, SV *sv)
- newUNOP
- Constructs, checks, and returns an op of any unary type. type is
the opcode. flags gives the eight bits of "op_flags",
except that "OPf_KIDS" will be set automatically if required,
and, shifted up eight bits, the eight bits of "op_private",
except that the bit with value 1 is automatically set. first
supplies an optional op to be the direct child of the unary op; it is
consumed by this function and become part of the constructed op tree.
OP * newUNOP(I32 type, I32 flags, OP *first)
- newWHENOP
- Constructs, checks, and returns an op tree expressing a "when"
block. cond supplies the test expression, and block supplies
the block that will be executed if the test evaluates to true; they are
consumed by this function and become part of the constructed op tree.
cond will be interpreted DWIMically, often as a comparison against
$_, and may be null to generate a "default" block.
OP * newWHENOP(OP *cond, OP *block)
- newWHILEOP
- Constructs, checks, and returns an op tree expressing a "while"
loop. This is a heavyweight loop, with structure that allows exiting the
loop by "last" and suchlike.
loop is an optional preconstructed "enterloop" op to use
in the loop; if it is null then a suitable op will be constructed
automatically. expr supplies the loop's controlling expression.
block supplies the main body of the loop, and cont
optionally supplies a "continue" block that operates as a second
half of the body. All of these optree inputs are consumed by this function
and become part of the constructed op tree.
flags gives the eight bits of "op_flags" for the
"leaveloop" op and, shifted up eight bits, the eight bits of
"op_private" for the "leaveloop" op, except that (in
both cases) some bits will be set automatically. debuggable is
currently unused and should always be 1. has_my can be supplied as
true to force the loop body to be enclosed in its own scope.
OP * newWHILEOP(I32 flags, I32 debuggable,
LOOP *loop, OP *expr, OP *block,
OP *cont, I32 has_my)
Optree Manipulation Functions¶
- ck_entersub_args_list
- Performs the default fixup of the arguments part of an
"entersub" op tree. This consists of applying list context to
each of the argument ops. This is the standard treatment used on a call
marked with "&", or a method call, or a call through a
subroutine reference, or any other call where the callee can't be
identified at compile time, or a call where the callee has no prototype.
OP * ck_entersub_args_list(OP *entersubop)
- ck_entersub_args_proto
- Performs the fixup of the arguments part of an "entersub" op
tree based on a subroutine prototype. This makes various modifications to
the argument ops, from applying context up to inserting "refgen"
ops, and checking the number and syntactic types of arguments, as directed
by the prototype. This is the standard treatment used on a subroutine
call, not marked with "&", where the callee can be
identified at compile time and has a prototype.
protosv supplies the subroutine prototype to be applied to the call.
It may be a normal defined scalar, of which the string value will be used.
Alternatively, for convenience, it may be a subroutine object (a
"CV*" that has been cast to "SV*") which has a
prototype. The prototype supplied, in whichever form, does not need to
match the actual callee referenced by the op tree.
If the argument ops disagree with the prototype, for example by having an
unacceptable number of arguments, a valid op tree is returned anyway. The
error is reflected in the parser state, normally resulting in a single
exception at the top level of parsing which covers all the compilation
errors that occurred. In the error message, the callee is referred to by
the name defined by the namegv parameter.
OP * ck_entersub_args_proto(OP *entersubop,
GV *namegv, SV *protosv)
- ck_entersub_args_proto_or_list
- Performs the fixup of the arguments part of an "entersub" op
tree either based on a subroutine prototype or using default list-context
processing. This is the standard treatment used on a subroutine call, not
marked with "&", where the callee can be identified at
compile time.
protosv supplies the subroutine prototype to be applied to the call,
or indicates that there is no prototype. It may be a normal scalar, in
which case if it is defined then the string value will be used as a
prototype, and if it is undefined then there is no prototype.
Alternatively, for convenience, it may be a subroutine object (a
"CV*" that has been cast to "SV*"), of which the
prototype will be used if it has one. The prototype (or lack thereof)
supplied, in whichever form, does not need to match the actual callee
referenced by the op tree.
If the argument ops disagree with the prototype, for example by having an
unacceptable number of arguments, a valid op tree is returned anyway. The
error is reflected in the parser state, normally resulting in a single
exception at the top level of parsing which covers all the compilation
errors that occurred. In the error message, the callee is referred to by
the name defined by the namegv parameter.
OP * ck_entersub_args_proto_or_list(OP *entersubop,
GV *namegv,
SV *protosv)
- cv_const_sv
- If "cv" is a constant sub eligible for inlining, returns the
constant value returned by the sub. Otherwise, returns NULL.
Constant subs can be created with "newCONSTSUB" or as described in
"Constant Functions" in perlsub.
SV* cv_const_sv(const CV *const cv)
- cv_get_call_checker
- Retrieves the function that will be used to fix up a call to cv.
Specifically, the function is applied to an "entersub" op tree
for a subroutine call, not marked with "&", where the callee
can be identified at compile time as cv.
The C-level function pointer is returned in *ckfun_p, and an SV
argument for it is returned in *ckobj_p. The function is intended
to be called in this manner:
entersubop = (*ckfun_p)(aTHX_ entersubop, namegv, (*ckobj_p));
In this call, entersubop is a pointer to the "entersub" op,
which may be replaced by the check function, and namegv is a GV
supplying the name that should be used by the check function to refer to
the callee of the "entersub" op if it needs to emit any
diagnostics. It is permitted to apply the check function in non-standard
situations, such as to a call to a different subroutine or to a method
call.
By default, the function is Perl_ck_entersub_args_proto_or_list, and the SV
parameter is cv itself. This implements standard prototype
processing. It can be changed, for a particular subroutine, by
"cv_set_call_checker".
void cv_get_call_checker(CV *cv,
Perl_call_checker *ckfun_p,
SV **ckobj_p)
- cv_set_call_checker
- Sets the function that will be used to fix up a call to cv.
Specifically, the function is applied to an "entersub" op tree
for a subroutine call, not marked with "&", where the callee
can be identified at compile time as cv.
The C-level function pointer is supplied in ckfun, and an SV argument
for it is supplied in ckobj. The function should be defined like
this:
STATIC OP * ckfun(pTHX_ OP *op, GV *namegv, SV *ckobj)
It is intended to be called in this manner:
entersubop = ckfun(aTHX_ entersubop, namegv, ckobj);
In this call, entersubop is a pointer to the "entersub" op,
which may be replaced by the check function, and namegv is a GV
supplying the name that should be used by the check function to refer to
the callee of the "entersub" op if it needs to emit any
diagnostics. It is permitted to apply the check function in non-standard
situations, such as to a call to a different subroutine or to a method
call.
The current setting for a particular CV can be retrieved by
"cv_get_call_checker".
void cv_set_call_checker(CV *cv,
Perl_call_checker ckfun,
SV *ckobj)
- LINKLIST
- Given the root of an optree, link the tree in execution order using the
"op_next" pointers and return the first op executed. If this has
already been done, it will not be redone, and "o->op_next"
will be returned. If "o->op_next" is not already set,
o should be at least an "UNOP".
OP* LINKLIST(OP *o)
- newCONSTSUB
- See "newCONSTSUB_flags".
CV* newCONSTSUB(HV* stash, const char* name, SV* sv)
- newCONSTSUB_flags
- Creates a constant sub equivalent to Perl "sub FOO () { 123 }"
which is eligible for inlining at compile-time.
Currently, the only useful value for "flags" is SVf_UTF8.
The newly created subroutine takes ownership of a reference to the passed in
SV.
Passing NULL for SV creates a constant sub equivalent to "sub BAR ()
{}", which won't be called if used as a destructor, but will suppress
the overhead of a call to "AUTOLOAD". (This form, however, isn't
eligible for inlining at compile time.)
CV* newCONSTSUB_flags(HV* stash, const char* name,
STRLEN len, U32 flags, SV* sv)
- newXS
- Used by "xsubpp" to hook up XSUBs as Perl subs. filename
needs to be static storage, as it is used directly as CvFILE(),
without a copy being made.
- op_append_elem
- Append an item to the list of ops contained directly within a list-type
op, returning the lengthened list. first is the list-type op, and
last is the op to append to the list. optype specifies the
intended opcode for the list. If first is not already a list of the
right type, it will be upgraded into one. If either first or
last is null, the other is returned unchanged.
OP * op_append_elem(I32 optype, OP *first, OP *last)
- op_append_list
- Concatenate the lists of ops contained directly within two list-type ops,
returning the combined list. first and last are the
list-type ops to concatenate. optype specifies the intended opcode
for the list. If either first or last is not already a list
of the right type, it will be upgraded into one. If either first or
last is null, the other is returned unchanged.
OP * op_append_list(I32 optype, OP *first, OP *last)
- OP_CLASS
- Return the class of the provided OP: that is, which of the *OP structures
it uses. For core ops this currently gets the information out of
PL_opargs, which does not always accurately reflect the type used. For
custom ops the type is returned from the registration, and it is up to the
registree to ensure it is accurate. The value returned will be one of the
OA_* constants from op.h.
U32 OP_CLASS(OP *o)
- OP_DESC
- Return a short description of the provided OP.
const char * OP_DESC(OP *o)
- op_linklist
- This function is the implementation of the "LINKLIST" macro. It
should not be called directly.
OP* op_linklist(OP *o)
- op_lvalue
- NOTE: this function is experimental and may change or be removed without
notice.
Propagate lvalue ("modifiable") context to an op and its children.
type represents the context type, roughly based on the type of op
that would do the modifying, although "local()" is represented
by OP_NULL, because it has no op type of its own (it is signalled by a
flag on the lvalue op).
This function detects things that can't be modified, such as
"$x+1", and generates errors for them. For example, "$x+1 =
2" would cause it to be called with an op of type OP_ADD and a
"type" argument of OP_SASSIGN.
It also flags things that need to behave specially in an lvalue context,
such as "$$x = 5" which might have to vivify a reference in $x.
OP * op_lvalue(OP *o, I32 type)
- OP_NAME
- Return the name of the provided OP. For core ops this looks up the name
from the op_type; for custom ops from the op_ppaddr.
const char * OP_NAME(OP *o)
- op_prepend_elem
- Prepend an item to the list of ops contained directly within a list-type
op, returning the lengthened list. first is the op to prepend to
the list, and last is the list-type op. optype specifies the
intended opcode for the list. If last is not already a list of the
right type, it will be upgraded into one. If either first or
last is null, the other is returned unchanged.
OP * op_prepend_elem(I32 optype, OP *first, OP *last)
- op_scope
- NOTE: this function is experimental and may change or be removed without
notice.
Wraps up an op tree with some additional ops so that at runtime a dynamic
scope will be created. The original ops run in the new dynamic scope, and
then, provided that they exit normally, the scope will be unwound. The
additional ops used to create and unwind the dynamic scope will normally
be an "enter"/"leave" pair, but a "scope" op
may be used instead if the ops are simple enough to not need the full
dynamic scope structure.
OP * op_scope(OP *o)
- OP_TYPE_IS
- Returns true if the given OP is not a NULL pointer and if it is of the
given type.
The negation of this macro, "OP_TYPE_ISNT" is also available as
well as "OP_TYPE_IS_NN" and "OP_TYPE_ISNT_NN" which
elide the NULL pointer check.
bool OP_TYPE_IS(OP *o, Optype type)
- OP_TYPE_IS_OR_WAS
- Returns true if the given OP is not a NULL pointer and if it is of the
given type or used to be before being replaced by an OP of type OP_NULL.
The negation of this macro, "OP_TYPE_ISNT_AND_WASNT" is also
available as well as "OP_TYPE_IS_OR_WAS_NN" and
"OP_TYPE_ISNT_AND_WASNT_NN" which elide the NULL pointer check.
bool OP_TYPE_IS_OR_WAS(OP *o, Optype type)
- rv2cv_op_cv
- Examines an op, which is expected to identify a subroutine at runtime, and
attempts to determine at compile time which subroutine it identifies. This
is normally used during Perl compilation to determine whether a prototype
can be applied to a function call. cvop is the op being considered,
normally an "rv2cv" op. A pointer to the identified subroutine
is returned, if it could be determined statically, and a null pointer is
returned if it was not possible to determine statically.
Currently, the subroutine can be identified statically if the RV that the
"rv2cv" is to operate on is provided by a suitable
"gv" or "const" op. A "gv" op is suitable if
the GV's CV slot is populated. A "const" op is suitable if the
constant value must be an RV pointing to a CV. Details of this process may
change in future versions of Perl. If the "rv2cv" op has the
"OPpENTERSUB_AMPER" flag set then no attempt is made to identify
the subroutine statically: this flag is used to suppress compile-time
magic on a subroutine call, forcing it to use default runtime behaviour.
If flags has the bit "RV2CVOPCV_MARK_EARLY" set, then the
handling of a GV reference is modified. If a GV was examined and its CV
slot was found to be empty, then the "gv" op has the
"OPpEARLY_CV" flag set. If the op is not optimised away, and the
CV slot is later populated with a subroutine having a prototype, that flag
eventually triggers the warning "called too early to check
prototype".
If flags has the bit "RV2CVOPCV_RETURN_NAME_GV" set, then
instead of returning a pointer to the subroutine it returns a pointer to
the GV giving the most appropriate name for the subroutine in this
context. Normally this is just the "CvGV" of the subroutine, but
for an anonymous ("CvANON") subroutine that is referenced
through a GV it will be the referencing GV. The resulting "GV*"
is cast to "CV*" to be returned. A null pointer is returned as
usual if there is no statically-determinable subroutine.
CV * rv2cv_op_cv(OP *cvop, U32 flags)
Pad Data Structures¶
- CvPADLIST
- NOTE: this function is experimental and may change or be removed without
notice.
CV's can have CvPADLIST(cv) set to point to a PADLIST. This is the CV's
scratchpad, which stores lexical variables and opcode temporary and
per-thread values.
For these purposes "formats" are a kind-of CV; eval""s
are too (except they're not callable at will and are always thrown away
after the eval"" is done executing). Require'd files are simply
evals without any outer lexical scope.
XSUBs don't have CvPADLIST set - dXSTARG fetches values from PL_curpad, but
that is really the callers pad (a slot of which is allocated by every
entersub).
The PADLIST has a C array where pads are stored.
The 0th entry of the PADLIST is a PADNAMELIST (which is actually just an AV,
but that may change) which represents the "names" or rather the
"static type information" for lexicals. The individual elements
of a PADNAMELIST are PADNAMEs (just SVs; but, again, that may change).
Future refactorings might stop the PADNAMELIST from being stored in the
PADLIST's array, so don't rely on it. See "PadlistNAMES".
The CvDEPTH'th entry of a PADLIST is a PAD (an AV) which is the stack frame
at that depth of recursion into the CV. The 0th slot of a frame AV is an
AV which is @_. Other entries are storage for variables and op targets.
Iterating over the PADNAMELIST iterates over all possible pad items. Pad
slots for targets (SVs_PADTMP) and GVs end up having &PL_sv_undef
"names", while slots for constants have &PL_sv_no
"names" (see pad_alloc()). That &PL_sv_no is used is
an implementation detail subject to change. To test for it, use
"PadnamePV(name) && !PadnameLEN(name)".
Only my/our variable (SvPADMY/PADNAME_isOUR) slots get valid names. The rest
are op targets/GVs/constants which are statically allocated or resolved at
compile time. These don't have names by which they can be looked up from
Perl code at run time through eval"" the way my/our variables
can be. Since they can't be looked up by "name" but only by
their index allocated at compile time (which is usually in
PL_op->op_targ), wasting a name SV for them doesn't make sense.
The SVs in the names AV have their PV being the name of the variable.
xlow+1..xhigh inclusive in the NV union is a range of cop_seq numbers for
which the name is valid (accessed through the macros COP_SEQ_RANGE_LOW and
_HIGH). During compilation, these fields may hold the special value
PERL_PADSEQ_INTRO to indicate various stages:
COP_SEQ_RANGE_LOW _HIGH
----------------- -----
PERL_PADSEQ_INTRO 0 variable not yet introduced: { my ($x
valid-seq# PERL_PADSEQ_INTRO variable in scope: { my ($x)
valid-seq# valid-seq# compilation of scope complete: { my ($x) }
For typed lexicals name SV is SVt_PVMG and SvSTASH points at the type. For
"our" lexicals, the type is also SVt_PVMG, with the SvOURSTASH
slot pointing at the stash of the associated global (so that duplicate
"our" declarations in the same package can be detected). SvUVX
is sometimes hijacked to store the generation number during compilation.
If PADNAME_OUTER (SvFAKE) is set on the name SV, then that slot in the frame
AV is a REFCNT'ed reference to a lexical from "outside". In this
case, the name SV does not use xlow and xhigh to store a cop_seq range,
since it is in scope throughout. Instead xhigh stores some flags
containing info about the real lexical (is it declared in an anon, and is
it capable of being instantiated multiple times?), and for fake ANONs,
xlow contains the index within the parent's pad where the lexical's value
is stored, to make cloning quicker.
If the 'name' is '&' the corresponding entry in the PAD is a CV
representing a possible closure. (PADNAME_OUTER and name of '&' is not
a meaningful combination currently but could become so if "my sub foo
{}" is implemented.)
Note that formats are treated as anon subs, and are cloned each time write
is called (if necessary).
The flag SVs_PADSTALE is cleared on lexicals each time the my() is
executed, and set on scope exit. This allows the 'Variable $x is not
available' warning to be generated in evals, such as
{ my $x = 1; sub f { eval '$x'} } f();
For state vars, SVs_PADSTALE is overloaded to mean 'not yet initialised'.
PADLIST * CvPADLIST(CV *cv)
- PadARRAY
- NOTE: this function is experimental and may change or be removed without
notice.
The C array of pad entries.
SV ** PadARRAY(PAD pad)
- PadlistARRAY
- NOTE: this function is experimental and may change or be removed without
notice.
The C array of a padlist, containing the pads. Only subscript it with
numbers >= 1, as the 0th entry is not guaranteed to remain usable.
PAD ** PadlistARRAY(PADLIST padlist)
- PadlistMAX
- NOTE: this function is experimental and may change or be removed without
notice.
The index of the last allocated space in the padlist. Note that the last pad
may be in an earlier slot. Any entries following it will be NULL in that
case.
SSize_t PadlistMAX(PADLIST padlist)
- PadlistNAMES
- NOTE: this function is experimental and may change or be removed without
notice.
The names associated with pad entries.
PADNAMELIST * PadlistNAMES(PADLIST padlist)
- PadlistNAMESARRAY
- NOTE: this function is experimental and may change or be removed without
notice.
The C array of pad names.
PADNAME ** PadlistNAMESARRAY(PADLIST padlist)
- PadlistNAMESMAX
- NOTE: this function is experimental and may change or be removed without
notice.
The index of the last pad name.
SSize_t PadlistNAMESMAX(PADLIST padlist)
- PadlistREFCNT
- NOTE: this function is experimental and may change or be removed without
notice.
The reference count of the padlist. Currently this is always 1.
U32 PadlistREFCNT(PADLIST padlist)
- PadMAX
- NOTE: this function is experimental and may change or be removed without
notice.
The index of the last pad entry.
SSize_t PadMAX(PAD pad)
- PadnameLEN
- NOTE: this function is experimental and may change or be removed without
notice.
The length of the name.
STRLEN PadnameLEN(PADNAME pn)
- PadnamelistARRAY
- NOTE: this function is experimental and may change or be removed without
notice.
The C array of pad names.
PADNAME ** PadnamelistARRAY(PADNAMELIST pnl)
- PadnamelistMAX
- NOTE: this function is experimental and may change or be removed without
notice.
The index of the last pad name.
SSize_t PadnamelistMAX(PADNAMELIST pnl)
- PadnamePV
- NOTE: this function is experimental and may change or be removed without
notice.
The name stored in the pad name struct. This returns NULL for a target or GV
slot.
char * PadnamePV(PADNAME pn)
- PadnameSV
- NOTE: this function is experimental and may change or be removed without
notice.
Returns the pad name as an SV. This is currently just "pn". It
will begin returning a new mortal SV if pad names ever stop being SVs.
SV * PadnameSV(PADNAME pn)
- PadnameUTF8
- NOTE: this function is experimental and may change or be removed without
notice.
Whether PadnamePV is in UTF8.
bool PadnameUTF8(PADNAME pn)
- pad_add_name_pvs
- Exactly like "pad_add_name_pvn", but takes a literal string
instead of a string/length pair.
PADOFFSET pad_add_name_pvs(const char *name, U32 flags,
HV *typestash, HV *ourstash)
- pad_findmy_pvs
- Exactly like "pad_findmy_pvn", but takes a literal string
instead of a string/length pair.
PADOFFSET pad_findmy_pvs(const char *name, U32 flags)
- pad_new
- Create a new padlist, updating the global variables for the
currently-compiling padlist to point to the new padlist. The following
flags can be OR'ed together:
padnew_CLONE this pad is for a cloned CV
padnew_SAVE save old globals on the save stack
padnew_SAVESUB also save extra stuff for start of sub
PADLIST * pad_new(int flags)
- PL_comppad
- NOTE: this function is experimental and may change or be removed without
notice.
During compilation, this points to the array containing the values part of
the pad for the currently-compiling code. (At runtime a CV may have many
such value arrays; at compile time just one is constructed.) At runtime,
this points to the array containing the currently-relevant values for the
pad for the currently-executing code.
- PL_comppad_name
- NOTE: this function is experimental and may change or be removed without
notice.
During compilation, this points to the array containing the names part of
the pad for the currently-compiling code.
- PL_curpad
- NOTE: this function is experimental and may change or be removed without
notice.
Points directly to the body of the "PL_comppad" array. (I.e., this
is "PAD_ARRAY(PL_comppad)".)
Per-Interpreter Variables¶
- PL_modglobal
- "PL_modglobal" is a general purpose, interpreter global HV for
use by extensions that need to keep information on a per-interpreter
basis. In a pinch, it can also be used as a symbol table for extensions to
share data among each other. It is a good idea to use keys prefixed by the
package name of the extension that owns the data.
HV* PL_modglobal
- PL_na
- A convenience variable which is typically used with "SvPV" when
one doesn't care about the length of the string. It is usually more
efficient to either declare a local variable and use that instead or to
use the "SvPV_nolen" macro.
STRLEN PL_na
- PL_opfreehook
- When non-"NULL", the function pointed by this variable will be
called each time an OP is freed with the corresponding OP as the argument.
This allows extensions to free any extra attribute they have locally
attached to an OP. It is also assured to first fire for the parent OP and
then for its kids.
When you replace this variable, it is considered a good practice to store
the possibly previously installed hook and that you recall it inside your
own.
Perl_ophook_t PL_opfreehook
- PL_peepp
- Pointer to the per-subroutine peephole optimiser. This is a function that
gets called at the end of compilation of a Perl subroutine (or
equivalently independent piece of Perl code) to perform fixups of some ops
and to perform small-scale optimisations. The function is called once for
each subroutine that is compiled, and is passed, as sole parameter, a
pointer to the op that is the entry point to the subroutine. It modifies
the op tree in place.
The peephole optimiser should never be completely replaced. Rather, add code
to it by wrapping the existing optimiser. The basic way to do this can be
seen in "Compile pass 3: peephole optimization" in perlguts. If
the new code wishes to operate on ops throughout the subroutine's
structure, rather than just at the top level, it is likely to be more
convenient to wrap the "PL_rpeepp" hook.
peep_t PL_peepp
- PL_rpeepp
- Pointer to the recursive peephole optimiser. This is a function that gets
called at the end of compilation of a Perl subroutine (or equivalently
independent piece of Perl code) to perform fixups of some ops and to
perform small-scale optimisations. The function is called once for each
chain of ops linked through their "op_next" fields; it is
recursively called to handle each side chain. It is passed, as sole
parameter, a pointer to the op that is at the head of the chain. It
modifies the op tree in place.
The peephole optimiser should never be completely replaced. Rather, add code
to it by wrapping the existing optimiser. The basic way to do this can be
seen in "Compile pass 3: peephole optimization" in perlguts. If
the new code wishes to operate only on ops at a subroutine's top level,
rather than throughout the structure, it is likely to be more convenient
to wrap the "PL_peepp" hook.
peep_t PL_rpeepp
- PL_sv_no
- This is the "false" SV. See "PL_sv_yes". Always refer
to this as &PL_sv_no.
SV PL_sv_no
- PL_sv_undef
- This is the "undef" SV. Always refer to this as
&PL_sv_undef.
SV PL_sv_undef
- PL_sv_yes
- This is the "true" SV. See "PL_sv_no". Always refer to
this as &PL_sv_yes.
SV PL_sv_yes
REGEXP Functions¶
- SvRX
- Convenience macro to get the REGEXP from a SV. This is approximately
equivalent to the following snippet:
if (SvMAGICAL(sv))
mg_get(sv);
if (SvROK(sv))
sv = MUTABLE_SV(SvRV(sv));
if (SvTYPE(sv) == SVt_REGEXP)
return (REGEXP*) sv;
NULL will be returned if a REGEXP* is not found.
REGEXP * SvRX(SV *sv)
- SvRXOK
- Returns a boolean indicating whether the SV (or the one it references) is
a REGEXP.
If you want to do something with the REGEXP* later use SvRX instead and
check for NULL.
bool SvRXOK(SV* sv)
Simple Exception Handling Macros¶
- dXCPT
- Set up necessary local variables for exception handling. See
"Exception Handling" in perlguts.
dXCPT;
- XCPT_CATCH
- Introduces a catch block. See "Exception Handling" in
perlguts.
- XCPT_RETHROW
- Rethrows a previously caught exception. See "Exception Handling"
in perlguts.
XCPT_RETHROW;
- XCPT_TRY_END
- Ends a try block. See "Exception Handling" in perlguts.
- XCPT_TRY_START
- Starts a try block. See "Exception Handling" in perlguts.
Stack Manipulation Macros¶
- dMARK
- Declare a stack marker variable, "mark", for the XSUB. See
"MARK" and "dORIGMARK".
dMARK;
- dORIGMARK
- Saves the original stack mark for the XSUB. See "ORIGMARK".
dORIGMARK;
- dSP
- Declares a local copy of perl's stack pointer for the XSUB, available via
the "SP" macro. See "SP".
dSP;
- EXTEND
- Used to extend the argument stack for an XSUB's return values. Once used,
guarantees that there is room for at least "nitems" to be pushed
onto the stack.
void EXTEND(SP, SSize_t nitems)
- MARK
- Stack marker variable for the XSUB. See "dMARK".
- mPUSHi
- Push an integer onto the stack. The stack must have room for this element.
Does not use "TARG". See also "PUSHi",
"mXPUSHi" and "XPUSHi".
void mPUSHi(IV iv)
- mPUSHn
- Push a double onto the stack. The stack must have room for this element.
Does not use "TARG". See also "PUSHn",
"mXPUSHn" and "XPUSHn".
void mPUSHn(NV nv)
- mPUSHp
- Push a string onto the stack. The stack must have room for this element.
The "len" indicates the length of the string. Does not use
"TARG". See also "PUSHp", "mXPUSHp" and
"XPUSHp".
void mPUSHp(char* str, STRLEN len)
- mPUSHs
- Push an SV onto the stack and mortalizes the SV. The stack must have room
for this element. Does not use "TARG". See also
"PUSHs" and "mXPUSHs".
void mPUSHs(SV* sv)
- mPUSHu
- Push an unsigned integer onto the stack. The stack must have room for this
element. Does not use "TARG". See also "PUSHu",
"mXPUSHu" and "XPUSHu".
void mPUSHu(UV uv)
- mXPUSHi
- Push an integer onto the stack, extending the stack if necessary. Does not
use "TARG". See also "XPUSHi", "mPUSHi" and
"PUSHi".
void mXPUSHi(IV iv)
- mXPUSHn
- Push a double onto the stack, extending the stack if necessary. Does not
use "TARG". See also "XPUSHn", "mPUSHn" and
"PUSHn".
void mXPUSHn(NV nv)
- mXPUSHp
- Push a string onto the stack, extending the stack if necessary. The
"len" indicates the length of the string. Does not use
"TARG". See also "XPUSHp", "mPUSHp" and
"PUSHp".
void mXPUSHp(char* str, STRLEN len)
- mXPUSHs
- Push an SV onto the stack, extending the stack if necessary and mortalizes
the SV. Does not use "TARG". See also "XPUSHs" and
"mPUSHs".
void mXPUSHs(SV* sv)
- mXPUSHu
- Push an unsigned integer onto the stack, extending the stack if necessary.
Does not use "TARG". See also "XPUSHu",
"mPUSHu" and "PUSHu".
void mXPUSHu(UV uv)
- ORIGMARK
- The original stack mark for the XSUB. See "dORIGMARK".
- POPi
- Pops an integer off the stack.
IV POPi
- POPl
- Pops a long off the stack.
long POPl
- POPn
- Pops a double off the stack.
NV POPn
- POPp
- Pops a string off the stack.
char* POPp
- POPpbytex
- Pops a string off the stack which must consist of bytes i.e. characters
< 256.
char* POPpbytex
- POPpx
- Pops a string off the stack. Identical to POPp. There are two names for
historical reasons.
char* POPpx
- POPs
- Pops an SV off the stack.
SV* POPs
- PUSHi
- Push an integer onto the stack. The stack must have room for this element.
Handles 'set' magic. Uses "TARG", so "dTARGET" or
"dXSTARG" should be called to declare it. Do not call multiple
"TARG"-oriented macros to return lists from XSUB's - see
"mPUSHi" instead. See also "XPUSHi" and
"mXPUSHi".
void PUSHi(IV iv)
- PUSHMARK
- Opening bracket for arguments on a callback. See "PUTBACK" and
perlcall.
void PUSHMARK(SP)
- PUSHmortal
- Push a new mortal SV onto the stack. The stack must have room for this
element. Does not use "TARG". See also "PUSHs",
"XPUSHmortal" and "XPUSHs".
void PUSHmortal()
- PUSHn
- Push a double onto the stack. The stack must have room for this element.
Handles 'set' magic. Uses "TARG", so "dTARGET" or
"dXSTARG" should be called to declare it. Do not call multiple
"TARG"-oriented macros to return lists from XSUB's - see
"mPUSHn" instead. See also "XPUSHn" and
"mXPUSHn".
void PUSHn(NV nv)
- PUSHp
- Push a string onto the stack. The stack must have room for this element.
The "len" indicates the length of the string. Handles 'set'
magic. Uses "TARG", so "dTARGET" or
"dXSTARG" should be called to declare it. Do not call multiple
"TARG"-oriented macros to return lists from XSUB's - see
"mPUSHp" instead. See also "XPUSHp" and
"mXPUSHp".
void PUSHp(char* str, STRLEN len)
- PUSHs
- Push an SV onto the stack. The stack must have room for this element. Does
not handle 'set' magic. Does not use "TARG". See also
"PUSHmortal", "XPUSHs" and "XPUSHmortal".
void PUSHs(SV* sv)
- PUSHu
- Push an unsigned integer onto the stack. The stack must have room for this
element. Handles 'set' magic. Uses "TARG", so
"dTARGET" or "dXSTARG" should be called to declare it.
Do not call multiple "TARG"-oriented macros to return lists from
XSUB's - see "mPUSHu" instead. See also "XPUSHu" and
"mXPUSHu".
void PUSHu(UV uv)
- PUTBACK
- Closing bracket for XSUB arguments. This is usually handled by
"xsubpp". See "PUSHMARK" and perlcall for other uses.
PUTBACK;
- SP
- Stack pointer. This is usually handled by "xsubpp". See
"dSP" and "SPAGAIN".
- SPAGAIN
- Refetch the stack pointer. Used after a callback. See perlcall.
SPAGAIN;
- XPUSHi
- Push an integer onto the stack, extending the stack if necessary. Handles
'set' magic. Uses "TARG", so "dTARGET" or
"dXSTARG" should be called to declare it. Do not call multiple
"TARG"-oriented macros to return lists from XSUB's - see
"mXPUSHi" instead. See also "PUSHi" and
"mPUSHi".
void XPUSHi(IV iv)
- XPUSHmortal
- Push a new mortal SV onto the stack, extending the stack if necessary.
Does not use "TARG". See also "XPUSHs",
"PUSHmortal" and "PUSHs".
void XPUSHmortal()
- XPUSHn
- Push a double onto the stack, extending the stack if necessary. Handles
'set' magic. Uses "TARG", so "dTARGET" or
"dXSTARG" should be called to declare it. Do not call multiple
"TARG"-oriented macros to return lists from XSUB's - see
"mXPUSHn" instead. See also "PUSHn" and
"mPUSHn".
void XPUSHn(NV nv)
- XPUSHp
- Push a string onto the stack, extending the stack if necessary. The
"len" indicates the length of the string. Handles 'set' magic.
Uses "TARG", so "dTARGET" or "dXSTARG"
should be called to declare it. Do not call multiple
"TARG"-oriented macros to return lists from XSUB's - see
"mXPUSHp" instead. See also "PUSHp" and
"mPUSHp".
void XPUSHp(char* str, STRLEN len)
- XPUSHs
- Push an SV onto the stack, extending the stack if necessary. Does not
handle 'set' magic. Does not use "TARG". See also
"XPUSHmortal", "PUSHs" and "PUSHmortal".
void XPUSHs(SV* sv)
- XPUSHu
- Push an unsigned integer onto the stack, extending the stack if necessary.
Handles 'set' magic. Uses "TARG", so "dTARGET" or
"dXSTARG" should be called to declare it. Do not call multiple
"TARG"-oriented macros to return lists from XSUB's - see
"mXPUSHu" instead. See also "PUSHu" and
"mPUSHu".
void XPUSHu(UV uv)
- XSRETURN
- Return from XSUB, indicating number of items on the stack. This is usually
handled by "xsubpp".
void XSRETURN(int nitems)
- XSRETURN_EMPTY
- Return an empty list from an XSUB immediately.
XSRETURN_EMPTY;
- XSRETURN_IV
- Return an integer from an XSUB immediately. Uses "XST_mIV".
void XSRETURN_IV(IV iv)
- XSRETURN_NO
- Return &PL_sv_no from an XSUB immediately. Uses "XST_mNO".
XSRETURN_NO;
- XSRETURN_NV
- Return a double from an XSUB immediately. Uses "XST_mNV".
void XSRETURN_NV(NV nv)
- XSRETURN_PV
- Return a copy of a string from an XSUB immediately. Uses
"XST_mPV".
void XSRETURN_PV(char* str)
- XSRETURN_UNDEF
- Return &PL_sv_undef from an XSUB immediately. Uses
"XST_mUNDEF".
XSRETURN_UNDEF;
- XSRETURN_UV
- Return an integer from an XSUB immediately. Uses "XST_mUV".
void XSRETURN_UV(IV uv)
- XSRETURN_YES
- Return &PL_sv_yes from an XSUB immediately. Uses "XST_mYES".
XSRETURN_YES;
- XST_mIV
- Place an integer into the specified position "pos" on the stack.
The value is stored in a new mortal SV.
void XST_mIV(int pos, IV iv)
- XST_mNO
- Place &PL_sv_no into the specified position "pos" on the
stack.
void XST_mNO(int pos)
- XST_mNV
- Place a double into the specified position "pos" on the stack.
The value is stored in a new mortal SV.
void XST_mNV(int pos, NV nv)
- XST_mPV
- Place a copy of a string into the specified position "pos" on
the stack. The value is stored in a new mortal SV.
void XST_mPV(int pos, char* str)
- XST_mUNDEF
- Place &PL_sv_undef into the specified position "pos" on the
stack.
void XST_mUNDEF(int pos)
- XST_mYES
- Place &PL_sv_yes into the specified position "pos" on the
stack.
void XST_mYES(int pos)
SV Flags¶
- svtype
- An enum of flags for Perl types. These are found in the file sv.h
in the "svtype" enum. Test these flags with the
"SvTYPE" macro.
The types are:
SVt_NULL
SVt_IV
SVt_NV
SVt_RV
SVt_PV
SVt_PVIV
SVt_PVNV
SVt_PVMG
SVt_INVLIST
SVt_REGEXP
SVt_PVGV
SVt_PVLV
SVt_PVAV
SVt_PVHV
SVt_PVCV
SVt_PVFM
SVt_PVIO
These are most easily explained from the bottom up.
SVt_PVIO is for I/O objects, SVt_PVFM for formats, SVt_PVCV for subroutines,
SVt_PVHV for hashes and SVt_PVAV for arrays.
All the others are scalar types, that is, things that can be bound to a
"$" variable. For these, the internal types are mostly
orthogonal to types in the Perl language.
Hence, checking "SvTYPE(sv) < SVt_PVAV" is the best way to see
whether something is a scalar.
SVt_PVGV represents a typeglob. If !SvFAKE(sv), then it is a real,
incoercible typeglob. If SvFAKE(sv), then it is a scalar to which a
typeglob has been assigned. Assigning to it again will stop it from being
a typeglob. SVt_PVLV represents a scalar that delegates to another scalar
behind the scenes. It is used, e.g., for the return value of
"substr" and for tied hash and array elements. It can hold any
scalar value, including a typeglob. SVt_REGEXP is for regular expressions.
SVt_INVLIST is for Perl core internal use only.
SVt_PVMG represents a "normal" scalar (not a typeglob, regular
expression, or delegate). Since most scalars do not need all the internal
fields of a PVMG, we save memory by allocating smaller structs when
possible. All the other types are just simpler forms of SVt_PVMG, with
fewer internal fields.
SVt_NULL can only hold undef. SVt_IV can hold undef, an integer, or a
reference. (SVt_RV is an alias for SVt_IV, which exists for backward
compatibility.) SVt_NV can hold any of those or a double. SVt_PV can only
hold undef or a string. SVt_PVIV is a superset of SVt_PV and SVt_IV.
SVt_PVNV is similar. SVt_PVMG can hold anything SVt_PVNV can hold, but it
can, but does not have to, be blessed or magical.
- SVt_INVLIST
- Type flag for scalars. See "svtype".
- SVt_IV
- Type flag for scalars. See "svtype".
- SVt_NULL
- Type flag for scalars. See "svtype".
- SVt_NV
- Type flag for scalars. See "svtype".
- SVt_PV
- Type flag for scalars. See "svtype".
- SVt_PVAV
- Type flag for arrays. See "svtype".
- SVt_PVCV
- Type flag for subroutines. See "svtype".
- SVt_PVFM
- Type flag for formats. See "svtype".
- SVt_PVGV
- Type flag for typeglobs. See "svtype".
- SVt_PVHV
- Type flag for hashes. See "svtype".
- SVt_PVIO
- Type flag for I/O objects. See "svtype".
- SVt_PVIV
- Type flag for scalars. See "svtype".
- SVt_PVLV
- Type flag for scalars. See "svtype".
- SVt_PVMG
- Type flag for scalars. See "svtype".
- SVt_PVNV
- Type flag for scalars. See "svtype".
- SVt_REGEXP
- Type flag for regular expressions. See "svtype".
SV Manipulation Functions¶
- boolSV
- Returns a true SV if "b" is a true value, or a false SV if
"b" is 0.
See also "PL_sv_yes" and "PL_sv_no".
SV * boolSV(bool b)
- croak_xs_usage
- A specialised variant of "croak()" for emitting the usage
message for xsubs
croak_xs_usage(cv, "eee_yow");
works out the package name and subroutine name from "cv", and then
calls "croak()". Hence if "cv" is &ouch::awk, it
would call "croak" as:
Perl_croak(aTHX_ "Usage: %"SVf"::%"SVf"(%s)", "ouch" "awk", "eee_yow");
void croak_xs_usage(const CV *const cv,
const char *const params)
- get_sv
- Returns the SV of the specified Perl scalar. "flags" are passed
to "gv_fetchpv". If "GV_ADD" is set and the Perl
variable does not exist then it will be created. If "flags" is
zero and the variable does not exist then NULL is returned.
NOTE: the perl_ form of this function is deprecated.
SV* get_sv(const char *name, I32 flags)
- newRV_inc
- Creates an RV wrapper for an SV. The reference count for the original SV
is incremented.
SV* newRV_inc(SV* sv)
- newSVpadname
- NOTE: this function is experimental and may change or be removed without
notice.
Creates a new SV containing the pad name. This is currently identical to
"newSVsv", but pad names may cease being SVs at some point, so
"newSVpadname" is preferable.
SV* newSVpadname(PADNAME *pn)
- newSVpvn_utf8
- Creates a new SV and copies a string (which may contain "NUL"
("\0") characters) into it. If utf8 is true, calls
"SvUTF8_on" on the new SV. Implemented as a wrapper around
"newSVpvn_flags".
SV* newSVpvn_utf8(NULLOK const char* s, STRLEN len,
U32 utf8)
- SvCUR
- Returns the length of the string which is in the SV. See
"SvLEN".
STRLEN SvCUR(SV* sv)
- SvCUR_set
- Set the current length of the string which is in the SV. See
"SvCUR" and "SvIV_set".
void SvCUR_set(SV* sv, STRLEN len)
- SvEND
- Returns a pointer to the spot just after the last character in the string
which is in the SV, where there is usually a trailing "NUL"
character (even though Perl scalars do not strictly require it). See
"SvCUR". Access the character as *(SvEND(sv)).
Warning: If "SvCUR" is equal to "SvLEN", then
"SvEND" points to unallocated memory.
char* SvEND(SV* sv)
- SvGAMAGIC
- Returns true if the SV has get magic or overloading. If either is true
then the scalar is active data, and has the potential to return a new
value every time it is accessed. Hence you must be careful to only read it
once per user logical operation and work with that returned value. If
neither is true then the scalar's value cannot change unless written to.
U32 SvGAMAGIC(SV* sv)
- SvGROW
- Expands the character buffer in the SV so that it has room for the
indicated number of bytes (remember to reserve space for an extra trailing
"NUL" character). Calls "sv_grow" to perform the
expansion if necessary. Returns a pointer to the character buffer. SV must
be of type >= SVt_PV. One alternative is to call "sv_grow" if
you are not sure of the type of SV.
char * SvGROW(SV* sv, STRLEN len)
- SvIOK
- Returns a U32 value indicating whether the SV contains an integer.
U32 SvIOK(SV* sv)
- SvIOKp
- Returns a U32 value indicating whether the SV contains an integer. Checks
the private setting. Use "SvIOK" instead.
U32 SvIOKp(SV* sv)
- SvIOK_notUV
- Returns a boolean indicating whether the SV contains a signed integer.
bool SvIOK_notUV(SV* sv)
- SvIOK_off
- Unsets the IV status of an SV.
void SvIOK_off(SV* sv)
- SvIOK_on
- Tells an SV that it is an integer.
void SvIOK_on(SV* sv)
- SvIOK_only
- Tells an SV that it is an integer and disables all other OK bits.
void SvIOK_only(SV* sv)
- SvIOK_only_UV
- Tells an SV that it is an unsigned integer and disables all other OK bits.
void SvIOK_only_UV(SV* sv)
- SvIOK_UV
- Returns a boolean indicating whether the SV contains an integer that must
be interpreted as unsigned. A non-negative integer whose value is within
the range of both an IV and a UV may be be flagged as either SvUOK or
SVIOK.
bool SvIOK_UV(SV* sv)
- SvIsCOW
- Returns a U32 value indicating whether the SV is Copy-On-Write (either
shared hash key scalars, or full Copy On Write scalars if 5.9.0 is
configured for COW).
U32 SvIsCOW(SV* sv)
- SvIsCOW_shared_hash
- Returns a boolean indicating whether the SV is Copy-On-Write shared hash
key scalar.
bool SvIsCOW_shared_hash(SV* sv)
- SvIV
- Coerces the given SV to an integer and returns it. See "SvIVx"
for a version which guarantees to evaluate sv only once.
IV SvIV(SV* sv)
- SvIVX
- Returns the raw value in the SV's IV slot, without checks or conversions.
Only use when you are sure SvIOK is true. See also "SvIV()".
IV SvIVX(SV* sv)
- SvIVx
- Coerces the given SV to an integer and returns it. Guarantees to evaluate
"sv" only once. Only use this if "sv" is an expression
with side effects, otherwise use the more efficient "SvIV".
IV SvIVx(SV* sv)
- SvIV_nomg
- Like "SvIV" but doesn't process magic.
IV SvIV_nomg(SV* sv)
- SvIV_set
- Set the value of the IV pointer in sv to val. It is possible to perform
the same function of this macro with an lvalue assignment to
"SvIVX". With future Perls, however, it will be more efficient
to use "SvIV_set" instead of the lvalue assignment to
"SvIVX".
void SvIV_set(SV* sv, IV val)
- SvLEN
- Returns the size of the string buffer in the SV, not including any part
attributable to "SvOOK". See "SvCUR".
STRLEN SvLEN(SV* sv)
- SvLEN_set
- Set the actual length of the string which is in the SV. See
"SvIV_set".
void SvLEN_set(SV* sv, STRLEN len)
- SvMAGIC_set
- Set the value of the MAGIC pointer in sv to val. See "SvIV_set".
void SvMAGIC_set(SV* sv, MAGIC* val)
- SvNIOK
- Returns a U32 value indicating whether the SV contains a number, integer
or double.
U32 SvNIOK(SV* sv)
- SvNIOKp
- Returns a U32 value indicating whether the SV contains a number, integer
or double. Checks the private setting. Use "SvNIOK"
instead.
U32 SvNIOKp(SV* sv)
- SvNIOK_off
- Unsets the NV/IV status of an SV.
void SvNIOK_off(SV* sv)
- SvNOK
- Returns a U32 value indicating whether the SV contains a double.
U32 SvNOK(SV* sv)
- SvNOKp
- Returns a U32 value indicating whether the SV contains a double. Checks
the private setting. Use "SvNOK" instead.
U32 SvNOKp(SV* sv)
- SvNOK_off
- Unsets the NV status of an SV.
void SvNOK_off(SV* sv)
- SvNOK_on
- Tells an SV that it is a double.
void SvNOK_on(SV* sv)
- SvNOK_only
- Tells an SV that it is a double and disables all other OK bits.
void SvNOK_only(SV* sv)
- SvNV
- Coerce the given SV to a double and return it. See "SvNVx" for a
version which guarantees to evaluate sv only once.
NV SvNV(SV* sv)
- SvNVX
- Returns the raw value in the SV's NV slot, without checks or conversions.
Only use when you are sure SvNOK is true. See also "SvNV()".
NV SvNVX(SV* sv)
- SvNVx
- Coerces the given SV to a double and returns it. Guarantees to evaluate
"sv" only once. Only use this if "sv" is an expression
with side effects, otherwise use the more efficient "SvNV".
NV SvNVx(SV* sv)
- SvNV_nomg
- Like "SvNV" but doesn't process magic.
NV SvNV_nomg(SV* sv)
- SvNV_set
- Set the value of the NV pointer in sv to val. See "SvIV_set".
void SvNV_set(SV* sv, NV val)
- SvOK
- Returns a U32 value indicating whether the value is defined. This is only
meaningful for scalars.
U32 SvOK(SV* sv)
- SvOOK
- Returns a U32 indicating whether the pointer to the string buffer is
offset. This hack is used internally to speed up removal of characters
from the beginning of a SvPV. When SvOOK is true, then the start of the
allocated string buffer is actually "SvOOK_offset()" bytes
before SvPVX. This offset used to be stored in SvIVX, but is now stored
within the spare part of the buffer.
U32 SvOOK(SV* sv)
- SvOOK_offset
- Reads into len the offset from SvPVX back to the true start of the
allocated buffer, which will be non-zero if "sv_chop" has been
used to efficiently remove characters from start of the buffer.
Implemented as a macro, which takes the address of len, which must
be of type "STRLEN". Evaluates sv more than once. Sets
len to 0 if "SvOOK(sv)" is false.
void SvOOK_offset(NN SV*sv, STRLEN len)
- SvPOK
- Returns a U32 value indicating whether the SV contains a character string.
U32 SvPOK(SV* sv)
- SvPOKp
- Returns a U32 value indicating whether the SV contains a character string.
Checks the private setting. Use "SvPOK" instead.
U32 SvPOKp(SV* sv)
- SvPOK_off
- Unsets the PV status of an SV.
void SvPOK_off(SV* sv)
- SvPOK_on
- Tells an SV that it is a string.
void SvPOK_on(SV* sv)
- SvPOK_only
- Tells an SV that it is a string and disables all other OK bits. Will also
turn off the UTF-8 status.
void SvPOK_only(SV* sv)
- SvPOK_only_UTF8
- Tells an SV that it is a string and disables all other OK bits, and leaves
the UTF-8 status as it was.
void SvPOK_only_UTF8(SV* sv)
- SvPV
- Returns a pointer to the string in the SV, or a stringified form of the SV
if the SV does not contain a string. The SV may cache the stringified
version becoming "SvPOK". Handles 'get' magic. The
"len" variable will be set to the length of the string (this is
a macro, so don't use &len). See also "SvPVx" for a version
which guarantees to evaluate sv only once.
Note that there is no guarantee that the return value of "SvPV()"
is equal to "SvPVX(sv)", or that "SvPVX(sv)" contains
valid data, or that successive calls to "SvPV(sv)" will return
the same pointer value each time. This is due to the way that things like
overloading and Copy-On-Write are handled. In these cases, the return
value may point to a temporary buffer or similar. If you absolutely need
the SvPVX field to be valid (for example, if you intend to write to it),
then see "SvPV_force".
char* SvPV(SV* sv, STRLEN len)
- SvPVbyte
- Like "SvPV", but converts sv to byte representation first if
necessary.
char* SvPVbyte(SV* sv, STRLEN len)
- SvPVbytex
- Like "SvPV", but converts sv to byte representation first if
necessary. Guarantees to evaluate sv only once; use the more efficient
"SvPVbyte" otherwise.
char* SvPVbytex(SV* sv, STRLEN len)
- SvPVbytex_force
- Like "SvPV_force", but converts sv to byte representation first
if necessary. Guarantees to evaluate sv only once; use the more efficient
"SvPVbyte_force" otherwise.
char* SvPVbytex_force(SV* sv, STRLEN len)
- SvPVbyte_force
- Like "SvPV_force", but converts sv to byte representation first
if necessary.
char* SvPVbyte_force(SV* sv, STRLEN len)
- SvPVbyte_nolen
- Like "SvPV_nolen", but converts sv to byte representation first
if necessary.
char* SvPVbyte_nolen(SV* sv)
- SvPVutf8
- Like "SvPV", but converts sv to utf8 first if necessary.
char* SvPVutf8(SV* sv, STRLEN len)
- SvPVutf8x
- Like "SvPV", but converts sv to utf8 first if necessary.
Guarantees to evaluate sv only once; use the more efficient
"SvPVutf8" otherwise.
char* SvPVutf8x(SV* sv, STRLEN len)
- SvPVutf8x_force
- Like "SvPV_force", but converts sv to utf8 first if necessary.
Guarantees to evaluate sv only once; use the more efficient
"SvPVutf8_force" otherwise.
char* SvPVutf8x_force(SV* sv, STRLEN len)
- SvPVutf8_force
- Like "SvPV_force", but converts sv to utf8 first if necessary.
char* SvPVutf8_force(SV* sv, STRLEN len)
- SvPVutf8_nolen
- Like "SvPV_nolen", but converts sv to utf8 first if necessary.
char* SvPVutf8_nolen(SV* sv)
- SvPVX
- Returns a pointer to the physical string in the SV. The SV must contain a
string. Prior to 5.9.3 it is not safe to execute this macro unless the
SV's type >= SVt_PV.
This is also used to store the name of an autoloaded subroutine in an XS
AUTOLOAD routine. See "Autoloading with XSUBs" in perlguts.
char* SvPVX(SV* sv)
- SvPVx
- A version of "SvPV" which guarantees to evaluate "sv"
only once. Only use this if "sv" is an expression with side
effects, otherwise use the more efficient "SvPV".
char* SvPVx(SV* sv, STRLEN len)
- SvPV_force
- Like "SvPV" but will force the SV into containing a string
("SvPOK"), and only a string ("SvPOK_only"), by hook
or by crook. You need force if you are going to update the
"SvPVX" directly. Processes get magic.
Note that coercing an arbitrary scalar into a plain PV will potentially
strip useful data from it. For example if the SV was "SvROK",
then the referent will have its reference count decremented, and the SV
itself may be converted to an "SvPOK" scalar with a string
buffer containing a value such as "ARRAY(0x1234)".
char* SvPV_force(SV* sv, STRLEN len)
- SvPV_force_nomg
- Like "SvPV_force", but doesn't process get magic.
char* SvPV_force_nomg(SV* sv, STRLEN len)
- SvPV_nolen
- Like "SvPV" but doesn't set a length variable.
char* SvPV_nolen(SV* sv)
- SvPV_nomg
- Like "SvPV" but doesn't process magic.
char* SvPV_nomg(SV* sv, STRLEN len)
- SvPV_nomg_nolen
- Like "SvPV_nolen" but doesn't process magic.
char* SvPV_nomg_nolen(SV* sv)
- SvPV_set
- This is probably not what you want to use, you probably wanted
"sv_usepvn_flags" or "sv_setpvn" or
"sv_setpvs".
Set the value of the PV pointer in "sv" to the Perl allocated
"NUL"-terminated string "val". See also
"SvIV_set".
Remember to free the previous PV buffer. There are many things to check.
Beware that the existing pointer may be involved in copy-on-write or other
mischief, so do "SvOOK_off(sv)" and use
"sv_force_normal" or "SvPV_force" (or check the
SvIsCOW flag) first to make sure this modification is safe. Then finally,
if it is not a COW, call "SvPV_free" to free the previous PV
buffer.
void SvPV_set(SV* sv, char* val)
- SvREFCNT
- Returns the value of the object's reference count.
U32 SvREFCNT(SV* sv)
- SvREFCNT_dec
- Decrements the reference count of the given SV. sv may be NULL.
void SvREFCNT_dec(SV* sv)
- SvREFCNT_dec_NN
- Same as SvREFCNT_dec, but can only be used if you know sv is not
NULL. Since we don't have to check the NULLness, it's faster and smaller.
void SvREFCNT_dec_NN(SV* sv)
- SvREFCNT_inc
- Increments the reference count of the given SV, returning the SV.
All of the following SvREFCNT_inc* macros are optimized versions of
SvREFCNT_inc, and can be replaced with SvREFCNT_inc.
SV* SvREFCNT_inc(SV* sv)
- SvREFCNT_inc_NN
- Same as SvREFCNT_inc, but can only be used if you know sv is not
NULL. Since we don't have to check the NULLness, it's faster and smaller.
SV* SvREFCNT_inc_NN(SV* sv)
- SvREFCNT_inc_simple
- Same as SvREFCNT_inc, but can only be used with expressions without side
effects. Since we don't have to store a temporary value, it's faster.
SV* SvREFCNT_inc_simple(SV* sv)
- SvREFCNT_inc_simple_NN
- Same as SvREFCNT_inc_simple, but can only be used if you know sv is
not NULL. Since we don't have to check the NULLness, it's faster and
smaller.
SV* SvREFCNT_inc_simple_NN(SV* sv)
- SvREFCNT_inc_simple_void
- Same as SvREFCNT_inc_simple, but can only be used if you don't need the
return value. The macro doesn't need to return a meaningful value.
void SvREFCNT_inc_simple_void(SV* sv)
- SvREFCNT_inc_simple_void_NN
- Same as SvREFCNT_inc, but can only be used if you don't need the return
value, and you know that sv is not NULL. The macro doesn't need to
return a meaningful value, or check for NULLness, so it's smaller and
faster.
void SvREFCNT_inc_simple_void_NN(SV* sv)
- SvREFCNT_inc_void
- Same as SvREFCNT_inc, but can only be used if you don't need the return
value. The macro doesn't need to return a meaningful value.
void SvREFCNT_inc_void(SV* sv)
- SvREFCNT_inc_void_NN
- Same as SvREFCNT_inc, but can only be used if you don't need the return
value, and you know that sv is not NULL. The macro doesn't need to
return a meaningful value, or check for NULLness, so it's smaller and
faster.
void SvREFCNT_inc_void_NN(SV* sv)
- SvROK
- Tests if the SV is an RV.
U32 SvROK(SV* sv)
- SvROK_off
- Unsets the RV status of an SV.
void SvROK_off(SV* sv)
- SvROK_on
- Tells an SV that it is an RV.
void SvROK_on(SV* sv)
- SvRV
- Dereferences an RV to return the SV.
SV* SvRV(SV* sv)
- SvRV_set
- Set the value of the RV pointer in sv to val. See "SvIV_set".
void SvRV_set(SV* sv, SV* val)
- SvSTASH
- Returns the stash of the SV.
HV* SvSTASH(SV* sv)
- SvSTASH_set
- Set the value of the STASH pointer in sv to val. See "SvIV_set".
void SvSTASH_set(SV* sv, HV* val)
- SvTAINT
- Taints an SV if tainting is enabled, and if some input to the current
expression is tainted--usually a variable, but possibly also implicit
inputs such as locale settings. "SvTAINT" propagates that
taintedness to the outputs of an expression in a pessimistic fashion;
i.e., without paying attention to precisely which outputs are influenced
by which inputs.
void SvTAINT(SV* sv)
- SvTAINTED
- Checks to see if an SV is tainted. Returns TRUE if it is, FALSE if not.
bool SvTAINTED(SV* sv)
- SvTAINTED_off
- Untaints an SV. Be very careful with this routine, as it
short-circuits some of Perl's fundamental security features. XS module
authors should not use this function unless they fully understand all the
implications of unconditionally untainting the value. Untainting should be
done in the standard perl fashion, via a carefully crafted regexp, rather
than directly untainting variables.
void SvTAINTED_off(SV* sv)
- SvTAINTED_on
- Marks an SV as tainted if tainting is enabled.
void SvTAINTED_on(SV* sv)
- SvTRUE
- Returns a boolean indicating whether Perl would evaluate the SV as true or
false. See SvOK() for a defined/undefined test. Handles 'get' magic
unless the scalar is already SvPOK, SvIOK or SvNOK (the public, not the
private flags).
bool SvTRUE(SV* sv)
- SvTRUE_nomg
- Returns a boolean indicating whether Perl would evaluate the SV as true or
false. See SvOK() for a defined/undefined test. Does not handle
'get' magic.
bool SvTRUE_nomg(SV* sv)
- SvTYPE
- Returns the type of the SV. See "svtype".
svtype SvTYPE(SV* sv)
- SvUOK
- Returns a boolean indicating whether the SV contains an integer that must
be interpreted as unsigned. A non-negative integer whose value is within
the range of both an IV and a UV may be be flagged as either SvUOK or
SVIOK.
bool SvUOK(SV* sv)
- SvUPGRADE
- Used to upgrade an SV to a more complex form. Uses "sv_upgrade"
to perform the upgrade if necessary. See "svtype".
void SvUPGRADE(SV* sv, svtype type)
- SvUTF8
- Returns a U32 value indicating the UTF-8 status of an SV. If things are
set-up properly, this indicates whether or not the SV contains UTF-8
encoded data. You should use this after a call to SvPV() or
one of its variants, in case any call to string overloading updates the
internal flag.
U32 SvUTF8(SV* sv)
- SvUTF8_off
- Unsets the UTF-8 status of an SV (the data is not changed, just the flag).
Do not use frivolously.
void SvUTF8_off(SV *sv)
- SvUTF8_on
- Turn on the UTF-8 status of an SV (the data is not changed, just the
flag). Do not use frivolously.
void SvUTF8_on(SV *sv)
- SvUV
- Coerces the given SV to an unsigned integer and returns it. See
"SvUVx" for a version which guarantees to evaluate sv only once.
UV SvUV(SV* sv)
- SvUVX
- Returns the raw value in the SV's UV slot, without checks or conversions.
Only use when you are sure SvIOK is true. See also "SvUV()".
UV SvUVX(SV* sv)
- SvUVx
- Coerces the given SV to an unsigned integer and returns it. Guarantees to
evaluate "sv" only once. Only use this if "sv" is an
expression with side effects, otherwise use the more efficient
"SvUV".
UV SvUVx(SV* sv)
- SvUV_nomg
- Like "SvUV" but doesn't process magic.
UV SvUV_nomg(SV* sv)
- SvUV_set
- Set the value of the UV pointer in sv to val. See "SvIV_set".
void SvUV_set(SV* sv, UV val)
- SvVOK
- Returns a boolean indicating whether the SV contains a v-string.
bool SvVOK(SV* sv)
- sv_catpvn_nomg
- Like "sv_catpvn" but doesn't process magic.
void sv_catpvn_nomg(SV* sv, const char* ptr,
STRLEN len)
- sv_catpv_nomg
- Like "sv_catpv" but doesn't process magic.
void sv_catpv_nomg(SV* sv, const char* ptr)
- sv_catsv_nomg
- Like "sv_catsv" but doesn't process magic.
void sv_catsv_nomg(SV* dsv, SV* ssv)
- sv_derived_from
- Exactly like "sv_derived_from_pv", but doesn't take a
"flags" parameter.
bool sv_derived_from(SV* sv, const char *const name)
- sv_derived_from_pv
- Exactly like "sv_derived_from_pvn", but takes a nul-terminated
string instead of a string/length pair.
bool sv_derived_from_pv(SV* sv,
const char *const name,
U32 flags)
- sv_derived_from_pvn
- Returns a boolean indicating whether the SV is derived from the specified
class at the C level. To check derivation at the Perl level, call
"isa()" as a normal Perl method.
Currently, the only significant value for "flags" is SVf_UTF8.
bool sv_derived_from_pvn(SV* sv,
const char *const name,
const STRLEN len, U32 flags)
- sv_derived_from_sv
- Exactly like "sv_derived_from_pvn", but takes the name string in
the form of an SV instead of a string/length pair.
bool sv_derived_from_sv(SV* sv, SV *namesv,
U32 flags)
- sv_does
- Like "sv_does_pv", but doesn't take a "flags"
parameter.
bool sv_does(SV* sv, const char *const name)
- sv_does_pv
- Like "sv_does_sv", but takes a nul-terminated string instead of
an SV.
bool sv_does_pv(SV* sv, const char *const name,
U32 flags)
- sv_does_pvn
- Like "sv_does_sv", but takes a string/length pair instead of an
SV.
bool sv_does_pvn(SV* sv, const char *const name,
const STRLEN len, U32 flags)
- sv_does_sv
- Returns a boolean indicating whether the SV performs a specific, named
role. The SV can be a Perl object or the name of a Perl class.
bool sv_does_sv(SV* sv, SV* namesv, U32 flags)
- sv_report_used
- Dump the contents of all SVs not yet freed (debugging aid).
void sv_report_used()
- sv_setsv_nomg
- Like "sv_setsv" but doesn't process magic.
void sv_setsv_nomg(SV* dsv, SV* ssv)
- sv_utf8_upgrade_nomg
- Like sv_utf8_upgrade, but doesn't do magic on "sv".
STRLEN sv_utf8_upgrade_nomg(NN SV *sv)
SV-Body Allocation¶
- looks_like_number
- Test if the content of an SV looks like a number (or is a number).
"Inf" and "Infinity" are treated as numbers (so will
not issue a non-numeric warning), even if your atof() doesn't grok
them. Get-magic is ignored.
I32 looks_like_number(SV *const sv)
- newRV_noinc
- Creates an RV wrapper for an SV. The reference count for the original SV
is not incremented.
SV* newRV_noinc(SV *const sv)
- newSV
- Creates a new SV. A non-zero "len" parameter indicates the
number of bytes of preallocated string space the SV should have. An extra
byte for a trailing "NUL" is also reserved. (SvPOK is not set
for the SV even if string space is allocated.) The reference count for the
new SV is set to 1.
In 5.9.3, newSV() replaces the older NEWSV() API, and drops
the first parameter, x, a debug aid which allowed callers to
identify themselves. This aid has been superseded by a new build option,
PERL_MEM_LOG (see "PERL_MEM_LOG" in perlhacktips). The older API
is still there for use in XS modules supporting older perls.
SV* newSV(const STRLEN len)
- newSVhek
- Creates a new SV from the hash key structure. It will generate scalars
that point to the shared string table where possible. Returns a new
(undefined) SV if the hek is NULL.
SV* newSVhek(const HEK *const hek)
- newSViv
- Creates a new SV and copies an integer into it. The reference count for
the SV is set to 1.
SV* newSViv(const IV i)
- newSVnv
- Creates a new SV and copies a floating point value into it. The reference
count for the SV is set to 1.
SV* newSVnv(const NV n)
- newSVpv
- Creates a new SV and copies a string (which may contain "NUL"
("\0") characters) into it. The reference count for the SV is
set to 1. If "len" is zero, Perl will compute the length using
strlen(), (which means if you use this option, that "s"
can't have embedded "NUL" characters and has to have a
terminating "NUL" byte).
For efficiency, consider using "newSVpvn" instead.
SV* newSVpv(const char *const s, const STRLEN len)
- newSVpvf
- Creates a new SV and initializes it with the string formatted like
"sprintf".
SV* newSVpvf(const char *const pat, ...)
- newSVpvn
- Creates a new SV and copies a string into it, which may contain
"NUL" characters ("\0") and other binary data. The
reference count for the SV is set to 1. Note that if "len" is
zero, Perl will create a zero length (Perl) string. You are responsible
for ensuring that the source buffer is at least "len" bytes
long. If the "buffer" argument is NULL the new SV will be
undefined.
SV* newSVpvn(const char *const s, const STRLEN len)
- newSVpvn_flags
- Creates a new SV and copies a string (which may contain "NUL"
("\0") characters) into it. The reference count for the SV is
set to 1. Note that if "len" is zero, Perl will create a zero
length string. You are responsible for ensuring that the source string is
at least "len" bytes long. If the "s" argument is NULL
the new SV will be undefined. Currently the only flag bits accepted are
"SVf_UTF8" and "SVs_TEMP". If "SVs_TEMP" is
set, then "sv_2mortal()" is called on the result before
returning. If "SVf_UTF8" is set, "s" is considered to
be in UTF-8 and the "SVf_UTF8" flag will be set on the new SV.
"newSVpvn_utf8()" is a convenience wrapper for this function,
defined as
#define newSVpvn_utf8(s, len, u) \
newSVpvn_flags((s), (len), (u) ? SVf_UTF8 : 0)
SV* newSVpvn_flags(const char *const s,
const STRLEN len,
const U32 flags)
- newSVpvn_share
- Creates a new SV with its SvPVX_const pointing to a shared string in the
string table. If the string does not already exist in the table, it is
created first. Turns on the SvIsCOW flag (or READONLY and FAKE in 5.16 and
earlier). If the "hash" parameter is non-zero, that value is
used; otherwise the hash is computed. The string's hash can later be
retrieved from the SV with the "SvSHARED_HASH()" macro. The idea
here is that as the string table is used for shared hash keys these
strings will have SvPVX_const == HeKEY and hash lookup will avoid string
compare.
SV* newSVpvn_share(const char* s, I32 len, U32 hash)
- newSVpvs
- Like "newSVpvn", but takes a literal "NUL"-terminated
string instead of a string/length pair.
SV* newSVpvs(const char* s)
- newSVpvs_flags
- Like "newSVpvn_flags", but takes a literal
"NUL"-terminated string instead of a string/length pair.
SV* newSVpvs_flags(const char* s, U32 flags)
- newSVpvs_share
- Like "newSVpvn_share", but takes a literal
"NUL"-terminated string instead of a string/length pair and
omits the hash parameter.
SV* newSVpvs_share(const char* s)
- newSVpv_share
- Like "newSVpvn_share", but takes a "NUL"-terminated
string instead of a string/length pair.
SV* newSVpv_share(const char* s, U32 hash)
- newSVrv
- Creates a new SV for the existing RV, "rv", to point to. If
"rv" is not an RV then it will be upgraded to one. If
"classname" is non-null then the new SV will be blessed in the
specified package. The new SV is returned and its reference count is 1.
The reference count 1 is owned by "rv".
SV* newSVrv(SV *const rv,
const char *const classname)
- newSVsv
- Creates a new SV which is an exact duplicate of the original SV. (Uses
"sv_setsv".)
SV* newSVsv(SV *const old)
- newSVuv
- Creates a new SV and copies an unsigned integer into it. The reference
count for the SV is set to 1.
SV* newSVuv(const UV u)
- newSV_type
- Creates a new SV, of the type specified. The reference count for the new
SV is set to 1.
SV* newSV_type(const svtype type)
- sv_2bool
- This macro is only used by sv_true() or its macro equivalent, and
only if the latter's argument is neither SvPOK, SvIOK nor SvNOK. It calls
sv_2bool_flags with the SV_GMAGIC flag.
bool sv_2bool(SV *const sv)
- sv_2bool_flags
- This function is only used by sv_true() and friends, and only if
the latter's argument is neither SvPOK, SvIOK nor SvNOK. If the flags
contain SV_GMAGIC, then it does an mg_get() first.
bool sv_2bool_flags(SV *sv, I32 flags)
- sv_2cv
- Using various gambits, try to get a CV from an SV; in addition, try if
possible to set *st and *gvp to the stash and GV associated with it. The
flags in "lref" are passed to gv_fetchsv.
CV* sv_2cv(SV* sv, HV **const st, GV **const gvp,
const I32 lref)
- sv_2io
- Using various gambits, try to get an IO from an SV: the IO slot if its a
GV; or the recursive result if we're an RV; or the IO slot of the symbol
named after the PV if we're a string.
'Get' magic is ignored on the sv passed in, but will be called on
"SvRV(sv)" if sv is an RV.
IO* sv_2io(SV *const sv)
- sv_2iv_flags
- Return the integer value of an SV, doing any necessary string conversion.
If flags includes SV_GMAGIC, does an mg_get() first. Normally used
via the "SvIV(sv)" and "SvIVx(sv)" macros.
IV sv_2iv_flags(SV *const sv, const I32 flags)
- sv_2mortal
- Marks an existing SV as mortal. The SV will be destroyed "soon",
either by an explicit call to FREETMPS, or by an implicit call at places
such as statement boundaries. SvTEMP() is turned on which means
that the SV's string buffer can be "stolen" if this SV is
copied. See also "sv_newmortal" and "sv_mortalcopy".
SV* sv_2mortal(SV *const sv)
- sv_2nv_flags
- Return the num value of an SV, doing any necessary string or integer
conversion. If flags includes SV_GMAGIC, does an mg_get() first.
Normally used via the "SvNV(sv)" and "SvNVx(sv)"
macros.
NV sv_2nv_flags(SV *const sv, const I32 flags)
- sv_2pvbyte
- Return a pointer to the byte-encoded representation of the SV, and set *lp
to its length. May cause the SV to be downgraded from UTF-8 as a
side-effect.
Usually accessed via the "SvPVbyte" macro.
char* sv_2pvbyte(SV *sv, STRLEN *const lp)
- sv_2pvutf8
- Return a pointer to the UTF-8-encoded representation of the SV, and set
*lp to its length. May cause the SV to be upgraded to UTF-8 as a
side-effect.
Usually accessed via the "SvPVutf8" macro.
char* sv_2pvutf8(SV *sv, STRLEN *const lp)
- sv_2pv_flags
- Returns a pointer to the string value of an SV, and sets *lp to its
length. If flags includes SV_GMAGIC, does an mg_get() first.
Coerces sv to a string if necessary. Normally invoked via the
"SvPV_flags" macro. "sv_2pv()" and
"sv_2pv_nomg" usually end up here too.
char* sv_2pv_flags(SV *const sv, STRLEN *const lp,
const I32 flags)
- sv_2uv_flags
- Return the unsigned integer value of an SV, doing any necessary string
conversion. If flags includes SV_GMAGIC, does an mg_get() first.
Normally used via the "SvUV(sv)" and "SvUVx(sv)"
macros.
UV sv_2uv_flags(SV *const sv, const I32 flags)
- sv_backoff
- Remove any string offset. You should normally use the
"SvOOK_off" macro wrapper instead.
int sv_backoff(SV *const sv)
- sv_bless
- Blesses an SV into a specified package. The SV must be an RV. The package
must be designated by its stash (see "gv_stashpv()"). The
reference count of the SV is unaffected.
SV* sv_bless(SV *const sv, HV *const stash)
- sv_catpv
- Concatenates the "NUL"-terminated string onto the end of the
string which is in the SV. If the SV has the UTF-8 status set, then the
bytes appended should be valid UTF-8. Handles 'get' magic, but not 'set'
magic. See "sv_catpv_mg".
void sv_catpv(SV *const sv, const char* ptr)
- sv_catpvf
- Processes its arguments like "sprintf" and appends the formatted
output to an SV. If the appended data contains "wide" characters
(including, but not limited to, SVs with a UTF-8 PV formatted with %s, and
characters >255 formatted with %c), the original SV might get upgraded
to UTF-8. Handles 'get' magic, but not 'set' magic. See
"sv_catpvf_mg". If the original SV was UTF-8, the pattern should
be valid UTF-8; if the original SV was bytes, the pattern should be too.
void sv_catpvf(SV *const sv, const char *const pat,
...)
- sv_catpvf_mg
- Like "sv_catpvf", but also handles 'set' magic.
void sv_catpvf_mg(SV *const sv,
const char *const pat, ...)
- sv_catpvn
- Concatenates the string onto the end of the string which is in the SV. The
"len" indicates number of bytes to copy. If the SV has the UTF-8
status set, then the bytes appended should be valid UTF-8. Handles 'get'
magic, but not 'set' magic. See "sv_catpvn_mg".
void sv_catpvn(SV *dsv, const char *sstr, STRLEN len)
- sv_catpvn_flags
- Concatenates the string onto the end of the string which is in the SV. The
"len" indicates number of bytes to copy. If the SV has the UTF-8
status set, then the bytes appended should be valid UTF-8. If
"flags" has the "SV_SMAGIC" bit set, will
"mg_set" on "dsv" afterwards if appropriate.
"sv_catpvn" and "sv_catpvn_nomg" are implemented in
terms of this function.
void sv_catpvn_flags(SV *const dstr,
const char *sstr,
const STRLEN len,
const I32 flags)
- sv_catpvs
- Like "sv_catpvn", but takes a literal string instead of a
string/length pair.
void sv_catpvs(SV* sv, const char* s)
- sv_catpvs_flags
- Like "sv_catpvn_flags", but takes a literal
"NUL"-terminated string instead of a string/length pair.
void sv_catpvs_flags(SV* sv, const char* s,
I32 flags)
- sv_catpvs_mg
- Like "sv_catpvn_mg", but takes a literal string instead of a
string/length pair.
void sv_catpvs_mg(SV* sv, const char* s)
- sv_catpvs_nomg
- Like "sv_catpvn_nomg", but takes a literal string instead of a
string/length pair.
void sv_catpvs_nomg(SV* sv, const char* s)
- sv_catpv_flags
- Concatenates the "NUL"-terminated string onto the end of the
string which is in the SV. If the SV has the UTF-8 status set, then the
bytes appended should be valid UTF-8. If "flags" has the
"SV_SMAGIC" bit set, will "mg_set" on the modified SV
if appropriate.
void sv_catpv_flags(SV *dstr, const char *sstr,
const I32 flags)
- sv_catpv_mg
- Like "sv_catpv", but also handles 'set' magic.
void sv_catpv_mg(SV *const sv, const char *const ptr)
- sv_catsv
- Concatenates the string from SV "ssv" onto the end of the string
in SV "dsv". If "ssv" is null, does nothing; otherwise
modifies only "dsv". Handles 'get' magic on both SVs, but no
'set' magic. See "sv_catsv_mg" and "sv_catsv_nomg".
void sv_catsv(SV *dstr, SV *sstr)
- sv_catsv_flags
- Concatenates the string from SV "ssv" onto the end of the string
in SV "dsv". If "ssv" is null, does nothing; otherwise
modifies only "dsv". If "flags" include
"SV_GMAGIC" bit set, will call "mg_get" on both SVs if
appropriate. If "flags" include "SV_SMAGIC",
"mg_set" will be called on the modified SV afterward, if
appropriate. "sv_catsv", "sv_catsv_nomg", and
"sv_catsv_mg" are implemented in terms of this function.
void sv_catsv_flags(SV *const dsv, SV *const ssv,
const I32 flags)
- sv_chop
- Efficient removal of characters from the beginning of the string buffer.
SvPOK(sv), or at least SvPOKp(sv), must be true and the "ptr"
must be a pointer to somewhere inside the string buffer. The
"ptr" becomes the first character of the adjusted string. Uses
the "OOK hack". On return, only SvPOK(sv) and SvPOKp(sv) among
the OK flags will be true.
Beware: after this function returns, "ptr" and SvPVX_const(sv) may
no longer refer to the same chunk of data.
The unfortunate similarity of this function's name to that of Perl's
"chop" operator is strictly coincidental. This function works
from the left; "chop" works from the right.
void sv_chop(SV *const sv, const char *const ptr)
- sv_clear
- Clear an SV: call any destructors, free up any memory used by the body,
and free the body itself. The SV's head is not freed, although its
type is set to all 1's so that it won't inadvertently be assumed to be
live during global destruction etc. This function should only be called
when REFCNT is zero. Most of the time you'll want to call
"sv_free()" (or its macro wrapper "SvREFCNT_dec")
instead.
void sv_clear(SV *const orig_sv)
- sv_cmp
- Compares the strings in two SVs. Returns -1, 0, or 1 indicating whether
the string in "sv1" is less than, equal to, or greater than the
string in "sv2". Is UTF-8 and 'use bytes' aware, handles get
magic, and will coerce its args to strings if necessary. See also
"sv_cmp_locale".
I32 sv_cmp(SV *const sv1, SV *const sv2)
- sv_cmp_flags
- Compares the strings in two SVs. Returns -1, 0, or 1 indicating whether
the string in "sv1" is less than, equal to, or greater than the
string in "sv2". Is UTF-8 and 'use bytes' aware and will coerce
its args to strings if necessary. If the flags include SV_GMAGIC, it
handles get magic. See also "sv_cmp_locale_flags".
I32 sv_cmp_flags(SV *const sv1, SV *const sv2,
const U32 flags)
- sv_cmp_locale
- Compares the strings in two SVs in a locale-aware manner. Is UTF-8 and
'use bytes' aware, handles get magic, and will coerce its args to strings
if necessary. See also "sv_cmp".
I32 sv_cmp_locale(SV *const sv1, SV *const sv2)
- sv_cmp_locale_flags
- Compares the strings in two SVs in a locale-aware manner. Is UTF-8 and
'use bytes' aware and will coerce its args to strings if necessary. If the
flags contain SV_GMAGIC, it handles get magic. See also
"sv_cmp_flags".
I32 sv_cmp_locale_flags(SV *const sv1,
SV *const sv2,
const U32 flags)
- sv_collxfrm
- This calls "sv_collxfrm_flags" with the SV_GMAGIC flag. See
"sv_collxfrm_flags".
char* sv_collxfrm(SV *const sv, STRLEN *const nxp)
- sv_collxfrm_flags
- Add Collate Transform magic to an SV if it doesn't already have it. If the
flags contain SV_GMAGIC, it handles get-magic.
Any scalar variable may carry PERL_MAGIC_collxfrm magic that contains the
scalar data of the variable, but transformed to such a format that a
normal memory comparison can be used to compare the data according to the
locale settings.
char* sv_collxfrm_flags(SV *const sv,
STRLEN *const nxp,
I32 const flags)
- sv_copypv_flags
- Implementation of sv_copypv and sv_copypv_nomg. Calls get magic iff flags
include SV_GMAGIC.
void sv_copypv_flags(SV *const dsv, SV *const ssv,
const I32 flags)
- sv_copypv_nomg
- Like sv_copypv, but doesn't invoke get magic first.
void sv_copypv_nomg(SV *const dsv, SV *const ssv)
- sv_dec
- Auto-decrement of the value in the SV, doing string to numeric conversion
if necessary. Handles 'get' magic and operator overloading.
void sv_dec(SV *const sv)
- sv_dec_nomg
- Auto-decrement of the value in the SV, doing string to numeric conversion
if necessary. Handles operator overloading. Skips handling 'get' magic.
void sv_dec_nomg(SV *const sv)
- sv_eq
- Returns a boolean indicating whether the strings in the two SVs are
identical. Is UTF-8 and 'use bytes' aware, handles get magic, and will
coerce its args to strings if necessary.
I32 sv_eq(SV* sv1, SV* sv2)
- sv_eq_flags
- Returns a boolean indicating whether the strings in the two SVs are
identical. Is UTF-8 and 'use bytes' aware and coerces its args to strings
if necessary. If the flags include SV_GMAGIC, it handles get-magic, too.
I32 sv_eq_flags(SV* sv1, SV* sv2, const U32 flags)
- sv_force_normal_flags
- Undo various types of fakery on an SV, where fakery means "more
than" a string: if the PV is a shared string, make a private copy; if
we're a ref, stop refing; if we're a glob, downgrade to an xpvmg; if we're
a copy-on-write scalar, this is the on-write time when we do the copy, and
is also used locally; if this is a vstring, drop the vstring magic. If
"SV_COW_DROP_PV" is set then a copy-on-write scalar drops its PV
buffer (if any) and becomes SvPOK_off rather than making a copy. (Used
where this scalar is about to be set to some other value.) In addition,
the "flags" parameter gets passed to
"sv_unref_flags()" when unreffing. "sv_force_normal"
calls this function with flags set to 0.
This function is expected to be used to signal to perl that this SV is about
to be written to, and any extra book-keeping needs to be taken care of.
Hence, it croaks on read-only values.
void sv_force_normal_flags(SV *const sv,
const U32 flags)
- sv_free
- Decrement an SV's reference count, and if it drops to zero, call
"sv_clear" to invoke destructors and free up any memory used by
the body; finally, deallocate the SV's head itself. Normally called via a
wrapper macro "SvREFCNT_dec".
void sv_free(SV *const sv)
- sv_gets
- Get a line from the filehandle and store it into the SV, optionally
appending to the currently-stored string. If "append" is not 0,
the line is appended to the SV instead of overwriting it.
"append" should be set to the byte offset that the appended
string should start at in the SV (typically, "SvCUR(sv)" is a
suitable choice).
char* sv_gets(SV *const sv, PerlIO *const fp,
I32 append)
- sv_grow
- Expands the character buffer in the SV. If necessary, uses
"sv_unref" and upgrades the SV to "SVt_PV". Returns a
pointer to the character buffer. Use the "SvGROW" wrapper
instead.
char* sv_grow(SV *const sv, STRLEN newlen)
- sv_inc
- Auto-increment of the value in the SV, doing string to numeric conversion
if necessary. Handles 'get' magic and operator overloading.
void sv_inc(SV *const sv)
- sv_inc_nomg
- Auto-increment of the value in the SV, doing string to numeric conversion
if necessary. Handles operator overloading. Skips handling 'get' magic.
void sv_inc_nomg(SV *const sv)
- sv_insert
- Inserts a string at the specified offset/length within the SV. Similar to
the Perl substr() function. Handles get magic.
void sv_insert(SV *const bigstr, const STRLEN offset,
const STRLEN len,
const char *const little,
const STRLEN littlelen)
- sv_insert_flags
- Same as "sv_insert", but the extra "flags" are passed
to the "SvPV_force_flags" that applies to "bigstr".
void sv_insert_flags(SV *const bigstr,
const STRLEN offset,
const STRLEN len,
const char *const little,
const STRLEN littlelen,
const U32 flags)
- sv_isa
- Returns a boolean indicating whether the SV is blessed into the specified
class. This does not check for subtypes; use "sv_derived_from"
to verify an inheritance relationship.
int sv_isa(SV* sv, const char *const name)
- sv_isobject
- Returns a boolean indicating whether the SV is an RV pointing to a blessed
object. If the SV is not an RV, or if the object is not blessed, then this
will return false.
int sv_isobject(SV* sv)
- sv_len
- Returns the length of the string in the SV. Handles magic and type
coercion and sets the UTF8 flag appropriately. See also "SvCUR",
which gives raw access to the xpv_cur slot.
STRLEN sv_len(SV *const sv)
- sv_len_utf8
- Returns the number of characters in the string in an SV, counting wide
UTF-8 bytes as a single character. Handles magic and type coercion.
STRLEN sv_len_utf8(SV *const sv)
- sv_magic
- Adds magic to an SV. First upgrades "sv" to type
"SVt_PVMG" if necessary, then adds a new magic item of type
"how" to the head of the magic list.
See "sv_magicext" (which "sv_magic" now calls) for a
description of the handling of the "name" and "namlen"
arguments.
You need to use "sv_magicext" to add magic to SvREADONLY SVs and
also to add more than one instance of the same 'how'.
void sv_magic(SV *const sv, SV *const obj,
const int how, const char *const name,
const I32 namlen)
- sv_magicext
- Adds magic to an SV, upgrading it if necessary. Applies the supplied
vtable and returns a pointer to the magic added.
Note that "sv_magicext" will allow things that
"sv_magic" will not. In particular, you can add magic to
SvREADONLY SVs, and add more than one instance of the same 'how'.
If "namlen" is greater than zero then a "savepvn"
copy of "name" is stored, if "namlen" is zero
then "name" is stored as-is and - as another special case - if
"(name && namlen == HEf_SVKEY)" then "name" is
assumed to contain an "SV*" and is stored as-is with its REFCNT
incremented.
(This is now used as a subroutine by "sv_magic".)
MAGIC * sv_magicext(SV *const sv, SV *const obj,
const int how,
const MGVTBL *const vtbl,
const char *const name,
const I32 namlen)
- sv_mortalcopy
- Creates a new SV which is a copy of the original SV (using
"sv_setsv"). The new SV is marked as mortal. It will be
destroyed "soon", either by an explicit call to FREETMPS, or by
an implicit call at places such as statement boundaries. See also
"sv_newmortal" and "sv_2mortal".
SV* sv_mortalcopy(SV *const oldsv)
- sv_newmortal
- Creates a new null SV which is mortal. The reference count of the SV is
set to 1. It will be destroyed "soon", either by an explicit
call to FREETMPS, or by an implicit call at places such as statement
boundaries. See also "sv_mortalcopy" and "sv_2mortal".
SV* sv_newmortal()
- sv_newref
- Increment an SV's reference count. Use the "SvREFCNT_inc()"
wrapper instead.
SV* sv_newref(SV *const sv)
- sv_pos_b2u
- Converts the value pointed to by offsetp from a count of bytes from the
start of the string, to a count of the equivalent number of UTF-8 chars.
Handles magic and type coercion.
Use "sv_pos_b2u_flags" in preference, which correctly handles
strings longer than 2Gb.
void sv_pos_b2u(SV *const sv, I32 *const offsetp)
- sv_pos_b2u_flags
- Converts the offset from a count of bytes from the start of the string, to
a count of the equivalent number of UTF-8 chars. Handles type coercion.
flags is passed to "SvPV_flags", and usually should be
"SV_GMAGIC|SV_CONST_RETURN" to handle magic.
STRLEN sv_pos_b2u_flags(SV *const sv,
STRLEN const offset, U32 flags)
- sv_pos_u2b
- Converts the value pointed to by offsetp from a count of UTF-8 chars from
the start of the string, to a count of the equivalent number of bytes; if
lenp is non-zero, it does the same to lenp, but this time starting from
the offset, rather than from the start of the string. Handles magic and
type coercion.
Use "sv_pos_u2b_flags" in preference, which correctly handles
strings longer than 2Gb.
void sv_pos_u2b(SV *const sv, I32 *const offsetp,
I32 *const lenp)
- sv_pos_u2b_flags
- Converts the offset from a count of UTF-8 chars from the start of the
string, to a count of the equivalent number of bytes; if lenp is non-zero,
it does the same to lenp, but this time starting from the offset, rather
than from the start of the string. Handles type coercion. flags is
passed to "SvPV_flags", and usually should be
"SV_GMAGIC|SV_CONST_RETURN" to handle magic.
STRLEN sv_pos_u2b_flags(SV *const sv, STRLEN uoffset,
STRLEN *const lenp, U32 flags)
- sv_pvbyten_force
- The backend for the "SvPVbytex_force" macro. Always use the
macro instead.
char* sv_pvbyten_force(SV *const sv, STRLEN *const lp)
- sv_pvn_force
- Get a sensible string out of the SV somehow. A private implementation of
the "SvPV_force" macro for compilers which can't cope with
complex macro expressions. Always use the macro instead.
char* sv_pvn_force(SV* sv, STRLEN* lp)
- sv_pvn_force_flags
- Get a sensible string out of the SV somehow. If "flags" has
"SV_GMAGIC" bit set, will "mg_get" on "sv"
if appropriate, else not. "sv_pvn_force" and
"sv_pvn_force_nomg" are implemented in terms of this function.
You normally want to use the various wrapper macros instead: see
"SvPV_force" and "SvPV_force_nomg"
char* sv_pvn_force_flags(SV *const sv,
STRLEN *const lp,
const I32 flags)
- sv_pvutf8n_force
- The backend for the "SvPVutf8x_force" macro. Always use the
macro instead.
char* sv_pvutf8n_force(SV *const sv, STRLEN *const lp)
- sv_reftype
- Returns a string describing what the SV is a reference to.
const char* sv_reftype(const SV *const sv, const int ob)
- sv_replace
- Make the first argument a copy of the second, then delete the original.
The target SV physically takes over ownership of the body of the source SV
and inherits its flags; however, the target keeps any magic it owns, and
any magic in the source is discarded. Note that this is a rather
specialist SV copying operation; most of the time you'll want to use
"sv_setsv" or one of its many macro front-ends.
void sv_replace(SV *const sv, SV *const nsv)
- sv_reset
- Underlying implementation for the "reset" Perl function. Note
that the perl-level function is vaguely deprecated.
void sv_reset(const char* s, HV *const stash)
- sv_rvweaken
- Weaken a reference: set the "SvWEAKREF" flag on this RV; give
the referred-to SV "PERL_MAGIC_backref" magic if it hasn't
already; and push a back-reference to this RV onto the array of
backreferences associated with that magic. If the RV is magical, set magic
will be called after the RV is cleared.
SV* sv_rvweaken(SV *const sv)
- sv_setiv
- Copies an integer into the given SV, upgrading first if necessary. Does
not handle 'set' magic. See also "sv_setiv_mg".
void sv_setiv(SV *const sv, const IV num)
- sv_setiv_mg
- Like "sv_setiv", but also handles 'set' magic.
void sv_setiv_mg(SV *const sv, const IV i)
- sv_setnv
- Copies a double into the given SV, upgrading first if necessary. Does not
handle 'set' magic. See also "sv_setnv_mg".
void sv_setnv(SV *const sv, const NV num)
- sv_setnv_mg
- Like "sv_setnv", but also handles 'set' magic.
void sv_setnv_mg(SV *const sv, const NV num)
- sv_setpv
- Copies a string into an SV. The string must be terminated with a
"NUL" character. Does not handle 'set' magic. See
"sv_setpv_mg".
void sv_setpv(SV *const sv, const char *const ptr)
- sv_setpvf
- Works like "sv_catpvf" but copies the text into the SV instead
of appending it. Does not handle 'set' magic. See
"sv_setpvf_mg".
void sv_setpvf(SV *const sv, const char *const pat,
...)
- sv_setpvf_mg
- Like "sv_setpvf", but also handles 'set' magic.
void sv_setpvf_mg(SV *const sv,
const char *const pat, ...)
- sv_setpviv
- Copies an integer into the given SV, also updating its string value. Does
not handle 'set' magic. See "sv_setpviv_mg".
void sv_setpviv(SV *const sv, const IV num)
- sv_setpviv_mg
- Like "sv_setpviv", but also handles 'set' magic.
void sv_setpviv_mg(SV *const sv, const IV iv)
- sv_setpvn
- Copies a string (possibly containing embedded "NUL" characters)
into an SV. The "len" parameter indicates the number of bytes to
be copied. If the "ptr" argument is NULL the SV will become
undefined. Does not handle 'set' magic. See "sv_setpvn_mg".
void sv_setpvn(SV *const sv, const char *const ptr,
const STRLEN len)
- sv_setpvn_mg
- Like "sv_setpvn", but also handles 'set' magic.
void sv_setpvn_mg(SV *const sv,
const char *const ptr,
const STRLEN len)
- sv_setpvs
- Like "sv_setpvn", but takes a literal string instead of a
string/length pair.
void sv_setpvs(SV* sv, const char* s)
- sv_setpvs_mg
- Like "sv_setpvn_mg", but takes a literal string instead of a
string/length pair.
void sv_setpvs_mg(SV* sv, const char* s)
- sv_setpv_mg
- Like "sv_setpv", but also handles 'set' magic.
void sv_setpv_mg(SV *const sv, const char *const ptr)
- sv_setref_iv
- Copies an integer into a new SV, optionally blessing the SV. The
"rv" argument will be upgraded to an RV. That RV will be
modified to point to the new SV. The "classname" argument
indicates the package for the blessing. Set "classname" to
"NULL" to avoid the blessing. The new SV will have a reference
count of 1, and the RV will be returned.
SV* sv_setref_iv(SV *const rv,
const char *const classname,
const IV iv)
- sv_setref_nv
- Copies a double into a new SV, optionally blessing the SV. The
"rv" argument will be upgraded to an RV. That RV will be
modified to point to the new SV. The "classname" argument
indicates the package for the blessing. Set "classname" to
"NULL" to avoid the blessing. The new SV will have a reference
count of 1, and the RV will be returned.
SV* sv_setref_nv(SV *const rv,
const char *const classname,
const NV nv)
- sv_setref_pv
- Copies a pointer into a new SV, optionally blessing the SV. The
"rv" argument will be upgraded to an RV. That RV will be
modified to point to the new SV. If the "pv" argument is NULL
then "PL_sv_undef" will be placed into the SV. The
"classname" argument indicates the package for the blessing. Set
"classname" to "NULL" to avoid the blessing. The new
SV will have a reference count of 1, and the RV will be returned.
Do not use with other Perl types such as HV, AV, SV, CV, because those
objects will become corrupted by the pointer copy process.
Note that "sv_setref_pvn" copies the string while this copies the
pointer.
SV* sv_setref_pv(SV *const rv,
const char *const classname,
void *const pv)
- sv_setref_pvn
- Copies a string into a new SV, optionally blessing the SV. The length of
the string must be specified with "n". The "rv"
argument will be upgraded to an RV. That RV will be modified to point to
the new SV. The "classname" argument indicates the package for
the blessing. Set "classname" to "NULL" to avoid the
blessing. The new SV will have a reference count of 1, and the RV will be
returned.
Note that "sv_setref_pv" copies the pointer while this copies the
string.
SV* sv_setref_pvn(SV *const rv,
const char *const classname,
const char *const pv,
const STRLEN n)
- sv_setref_pvs
- Like "sv_setref_pvn", but takes a literal string instead of a
string/length pair.
SV * sv_setref_pvs(const char* s)
- sv_setref_uv
- Copies an unsigned integer into a new SV, optionally blessing the SV. The
"rv" argument will be upgraded to an RV. That RV will be
modified to point to the new SV. The "classname" argument
indicates the package for the blessing. Set "classname" to
"NULL" to avoid the blessing. The new SV will have a reference
count of 1, and the RV will be returned.
SV* sv_setref_uv(SV *const rv,
const char *const classname,
const UV uv)
- sv_setsv
- Copies the contents of the source SV "ssv" into the destination
SV "dsv". The source SV may be destroyed if it is mortal, so
don't use this function if the source SV needs to be reused. Does not
handle 'set' magic on destination SV. Calls 'get' magic on source SV.
Loosely speaking, it performs a copy-by-value, obliterating any previous
content of the destination.
You probably want to use one of the assortment of wrappers, such as
"SvSetSV", "SvSetSV_nosteal", "SvSetMagicSV"
and "SvSetMagicSV_nosteal".
void sv_setsv(SV *dstr, SV *sstr)
- sv_setsv_flags
- Copies the contents of the source SV "ssv" into the destination
SV "dsv". The source SV may be destroyed if it is mortal, so
don't use this function if the source SV needs to be reused. Does not
handle 'set' magic. Loosely speaking, it performs a copy-by-value,
obliterating any previous content of the destination. If the
"flags" parameter has the "SV_GMAGIC" bit set, will
"mg_get" on "ssv" if appropriate, else not. If the
"flags" parameter has the "SV_NOSTEAL" bit set then
the buffers of temps will not be stolen. <sv_setsv> and
"sv_setsv_nomg" are implemented in terms of this function.
You probably want to use one of the assortment of wrappers, such as
"SvSetSV", "SvSetSV_nosteal", "SvSetMagicSV"
and "SvSetMagicSV_nosteal".
This is the primary function for copying scalars, and most other copy-ish
functions and macros use this underneath.
void sv_setsv_flags(SV *dstr, SV *sstr,
const I32 flags)
- sv_setsv_mg
- Like "sv_setsv", but also handles 'set' magic.
void sv_setsv_mg(SV *const dstr, SV *const sstr)
- sv_setuv
- Copies an unsigned integer into the given SV, upgrading first if
necessary. Does not handle 'set' magic. See also "sv_setuv_mg".
void sv_setuv(SV *const sv, const UV num)
- sv_setuv_mg
- Like "sv_setuv", but also handles 'set' magic.
void sv_setuv_mg(SV *const sv, const UV u)
- sv_tainted
- Test an SV for taintedness. Use "SvTAINTED" instead.
bool sv_tainted(SV *const sv)
- sv_true
- Returns true if the SV has a true value by Perl's rules. Use the
"SvTRUE" macro instead, which may call "sv_true()" or
may instead use an in-line version.
I32 sv_true(SV *const sv)
- sv_unmagic
- Removes all magic of type "type" from an SV.
int sv_unmagic(SV *const sv, const int type)
- sv_unmagicext
- Removes all magic of type "type" with the specified
"vtbl" from an SV.
int sv_unmagicext(SV *const sv, const int type,
MGVTBL *vtbl)
- sv_unref_flags
- Unsets the RV status of the SV, and decrements the reference count of
whatever was being referenced by the RV. This can almost be thought of as
a reversal of "newSVrv". The "cflags" argument can
contain "SV_IMMEDIATE_UNREF" to force the reference count to be
decremented (otherwise the decrementing is conditional on the reference
count being different from one or the reference being a readonly SV). See
"SvROK_off".
void sv_unref_flags(SV *const ref, const U32 flags)
- sv_untaint
- Untaint an SV. Use "SvTAINTED_off" instead.
void sv_untaint(SV *const sv)
- sv_upgrade
- Upgrade an SV to a more complex form. Generally adds a new body type to
the SV, then copies across as much information as possible from the old
body. It croaks if the SV is already in a more complex form than
requested. You generally want to use the "SvUPGRADE" macro
wrapper, which checks the type before calling "sv_upgrade", and
hence does not croak. See also "svtype".
void sv_upgrade(SV *const sv, svtype new_type)
- sv_usepvn_flags
- Tells an SV to use "ptr" to find its string value. Normally the
string is stored inside the SV, but sv_usepvn allows the SV to use an
outside string. The "ptr" should point to memory that was
allocated by Newx. It must be the start of a Newx-ed block of memory, and
not a pointer to the middle of it (beware of OOK and copy-on-write), and
not be from a non-Newx memory allocator like "malloc". The
string length, "len", must be supplied. By default this function
will "Renew" (i.e. realloc, move) the memory pointed to by
"ptr", so that pointer should not be freed or used by the
programmer after giving it to sv_usepvn, and neither should any pointers
from "behind" that pointer (e.g. ptr + 1) be used.
If "flags" & SV_SMAGIC is true, will call SvSETMAGIC. If
"flags" & SV_HAS_TRAILING_NUL is true, then
"ptr[len]" must be "NUL", and the realloc will be
skipped (i.e. the buffer is actually at least 1 byte longer than
"len", and already meets the requirements for storing in
"SvPVX").
void sv_usepvn_flags(SV *const sv, char* ptr,
const STRLEN len,
const U32 flags)
- sv_utf8_decode
- NOTE: this function is experimental and may change or be removed without
notice.
If the PV of the SV is an octet sequence in UTF-8 and contains a
multiple-byte character, the "SvUTF8" flag is turned on so that
it looks like a character. If the PV contains only single-byte characters,
the "SvUTF8" flag stays off. Scans PV for validity and returns
false if the PV is invalid UTF-8.
bool sv_utf8_decode(SV *const sv)
- sv_utf8_downgrade
- NOTE: this function is experimental and may change or be removed without
notice.
Attempts to convert the PV of an SV from characters to bytes. If the PV
contains a character that cannot fit in a byte, this conversion will fail;
in this case, either returns false or, if "fail_ok" is not true,
croaks.
This is not a general purpose Unicode to byte encoding interface: use the
Encode extension for that.
bool sv_utf8_downgrade(SV *const sv,
const bool fail_ok)
- sv_utf8_encode
- Converts the PV of an SV to UTF-8, but then turns the "SvUTF8"
flag off so that it looks like octets again.
void sv_utf8_encode(SV *const sv)
- sv_utf8_upgrade
- Converts the PV of an SV to its UTF-8-encoded form. Forces the SV to
string form if it is not already. Will "mg_get" on
"sv" if appropriate. Always sets the SvUTF8 flag to avoid future
validity checks even if the whole string is the same in UTF-8 as not.
Returns the number of bytes in the converted string
This is not a general purpose byte encoding to Unicode interface: use the
Encode extension for that.
STRLEN sv_utf8_upgrade(SV *sv)
- sv_utf8_upgrade_flags
- Converts the PV of an SV to its UTF-8-encoded form. Forces the SV to
string form if it is not already. Always sets the SvUTF8 flag to avoid
future validity checks even if all the bytes are invariant in UTF-8. If
"flags" has "SV_GMAGIC" bit set, will
"mg_get" on "sv" if appropriate, else not.
If "flags" has SV_FORCE_UTF8_UPGRADE set, this function assumes
that the PV will expand when converted to UTF-8, and skips the extra work
of checking for that. Typically this flag is used by a routine that has
already parsed the string and found such characters, and passes this
information on so that the work doesn't have to be repeated.
Returns the number of bytes in the converted string.
This is not a general purpose byte encoding to Unicode interface: use the
Encode extension for that.
STRLEN sv_utf8_upgrade_flags(SV *const sv,
const I32 flags)
- sv_utf8_upgrade_flags_grow
- Like sv_utf8_upgrade_flags, but has an additional parameter
"extra", which is the number of unused bytes the string of 'sv'
is guaranteed to have free after it upon return. This allows the caller to
reserve extra space that it intends to fill, to avoid extra grows.
"sv_utf8_upgrade", "sv_utf8_upgrade_nomg", and
"sv_utf8_upgrade_flags" are implemented in terms of this
function.
Returns the number of bytes in the converted string (not including the
spares).
STRLEN sv_utf8_upgrade_flags_grow(SV *const sv,
const I32 flags,
STRLEN extra)
- sv_utf8_upgrade_nomg
- Like sv_utf8_upgrade, but doesn't do magic on "sv".
STRLEN sv_utf8_upgrade_nomg(SV *sv)
- sv_vcatpvf
- Processes its arguments like "vsprintf" and appends the
formatted output to an SV. Does not handle 'set' magic. See
"sv_vcatpvf_mg".
Usually used via its frontend "sv_catpvf".
void sv_vcatpvf(SV *const sv, const char *const pat,
va_list *const args)
- sv_vcatpvfn
-
void sv_vcatpvfn(SV *const sv, const char *const pat,
const STRLEN patlen,
va_list *const args,
SV **const svargs, const I32 svmax,
bool *const maybe_tainted)
- sv_vcatpvfn_flags
- Processes its arguments like "vsprintf" and appends the
formatted output to an SV. Uses an array of SVs if the C style variable
argument list is missing (NULL). When running with taint checks enabled,
indicates via "maybe_tainted" if results are untrustworthy
(often due to the use of locales).
If called as "sv_vcatpvfn" or flags include "SV_GMAGIC",
calls get magic.
Usually used via one of its frontends "sv_vcatpvf" and
"sv_vcatpvf_mg".
void sv_vcatpvfn_flags(SV *const sv,
const char *const pat,
const STRLEN patlen,
va_list *const args,
SV **const svargs,
const I32 svmax,
bool *const maybe_tainted,
const U32 flags)
- sv_vcatpvf_mg
- Like "sv_vcatpvf", but also handles 'set' magic.
Usually used via its frontend "sv_catpvf_mg".
void sv_vcatpvf_mg(SV *const sv,
const char *const pat,
va_list *const args)
- sv_vsetpvf
- Works like "sv_vcatpvf" but copies the text into the SV instead
of appending it. Does not handle 'set' magic. See
"sv_vsetpvf_mg".
Usually used via its frontend "sv_setpvf".
void sv_vsetpvf(SV *const sv, const char *const pat,
va_list *const args)
- sv_vsetpvfn
- Works like "sv_vcatpvfn" but copies the text into the SV instead
of appending it.
Usually used via one of its frontends "sv_vsetpvf" and
"sv_vsetpvf_mg".
void sv_vsetpvfn(SV *const sv, const char *const pat,
const STRLEN patlen,
va_list *const args,
SV **const svargs, const I32 svmax,
bool *const maybe_tainted)
- sv_vsetpvf_mg
- Like "sv_vsetpvf", but also handles 'set' magic.
Usually used via its frontend "sv_setpvf_mg".
void sv_vsetpvf_mg(SV *const sv,
const char *const pat,
va_list *const args)
Unicode Support¶
- bytes_cmp_utf8
- Compares the sequence of characters (stored as octets) in "b",
"blen" with the sequence of characters (stored as UTF-8) in
"u", "ulen". Returns 0 if they are equal, -1 or -2 if
the first string is less than the second string, +1 or +2 if the first
string is greater than the second string.
-1 or +1 is returned if the shorter string was identical to the start of the
longer string. -2 or +2 is returned if there was a difference between
characters within the strings.
int bytes_cmp_utf8(const U8 *b, STRLEN blen,
const U8 *u, STRLEN ulen)
- bytes_from_utf8
- NOTE: this function is experimental and may change or be removed without
notice.
Converts a string "s" of length "len" from UTF-8 into
native byte encoding. Unlike "utf8_to_bytes" but like
"bytes_to_utf8", returns a pointer to the newly-created string,
and updates "len" to contain the new length. Returns the
original string if no conversion occurs, "len" is unchanged. Do
nothing if "is_utf8" points to 0. Sets "is_utf8" to 0
if "s" is converted or consisted entirely of characters that are
invariant in utf8 (i.e., US-ASCII on non-EBCDIC machines).
U8* bytes_from_utf8(const U8 *s, STRLEN *len,
bool *is_utf8)
- bytes_to_utf8
- NOTE: this function is experimental and may change or be removed without
notice.
Converts a string "s" of length "len" bytes from the
native encoding into UTF-8. Returns a pointer to the newly-created string,
and sets "len" to reflect the new length in bytes.
A "NUL" character will be written after the end of the string.
If you want to convert to UTF-8 from encodings other than the native (Latin1
or EBCDIC), see "sv_recode_to_utf8"().
U8* bytes_to_utf8(const U8 *s, STRLEN *len)
- foldEQ_utf8
- Returns true if the leading portions of the strings "s1" and
"s2" (either or both of which may be in UTF-8) are the same
case-insensitively; false otherwise. How far into the strings to compare
is determined by other input parameters.
If "u1" is true, the string "s1" is assumed to be in
UTF-8-encoded Unicode; otherwise it is assumed to be in native 8-bit
encoding. Correspondingly for "u2" with respect to
"s2".
If the byte length "l1" is non-zero, it says how far into
"s1" to check for fold equality. In other words,
"s1"+"l1" will be used as a goal to reach. The scan
will not be considered to be a match unless the goal is reached, and
scanning won't continue past that goal. Correspondingly for "l2"
with respect to "s2".
If "pe1" is non-NULL and the pointer it points to is not NULL,
that pointer is considered an end pointer to the position 1 byte past the
maximum point in "s1" beyond which scanning will not continue
under any circumstances. (This routine assumes that UTF-8 encoded input
strings are not malformed; malformed input can cause it to read past
"pe1"). This means that if both "l1" and
"pe1" are specified, and "pe1" is less than
"s1"+"l1", the match will never be successful because
it can never get as far as its goal (and in fact is asserted against).
Correspondingly for "pe2" with respect to "s2".
At least one of "s1" and "s2" must have a goal (at least
one of "l1" and "l2" must be non-zero), and if both
do, both have to be reached for a successful match. Also, if the fold of a
character is multiple characters, all of them must be matched (see tr21
reference below for 'folding').
Upon a successful match, if "pe1" is non-NULL, it will be set to
point to the beginning of the next character of "s1"
beyond what was matched. Correspondingly for "pe2" and
"s2".
For case-insensitiveness, the "casefolding" of Unicode is used
instead of upper/lowercasing both the characters, see
<http://www.unicode.org/unicode/reports/tr21/> (Case Mappings).
I32 foldEQ_utf8(const char *s1, char **pe1, UV l1,
bool u1, const char *s2, char **pe2,
UV l2, bool u2)
- is_ascii_string
- Returns true if the first "len" bytes of the string
"s" are the same whether or not the string is encoded in UTF-8
(or UTF-EBCDIC on EBCDIC machines). That is, if they are invariant. On
ASCII-ish machines, only ASCII characters fit this definition, hence the
function's name.
If "len" is 0, it will be calculated using strlen(s), (which means
if you use this option, that "s" can't have embedded
"NUL" characters and has to have a terminating "NUL"
byte).
See also "is_utf8_string"(), "is_utf8_string_loclen"(),
and "is_utf8_string_loc"().
bool is_ascii_string(const U8 *s, STRLEN len)
- is_utf8_char
- DEPRECATED! It is planned to remove this function from a future release of
Perl. Do not use it for new code; remove it from existing code.
Tests if some arbitrary number of bytes begins in a valid UTF-8 character.
Note that an INVARIANT (i.e. ASCII on non-EBCDIC machines) character is a
valid UTF-8 character. The actual number of bytes in the UTF-8 character
will be returned if it is valid, otherwise 0.
This function is deprecated due to the possibility that malformed input
could cause reading beyond the end of the input buffer. Use
"is_utf8_char_buf" instead.
STRLEN is_utf8_char(const U8 *s)
- is_utf8_char_buf
- Returns the number of bytes that comprise the first UTF-8 encoded
character in buffer "buf". "buf_end" should point to
one position beyond the end of the buffer. 0 is returned if
"buf" does not point to a complete, valid UTF-8 encoded
character.
Note that an INVARIANT character (i.e. ASCII on non-EBCDIC machines) is a
valid UTF-8 character.
STRLEN is_utf8_char_buf(const U8 *buf,
const U8 *buf_end)
- is_utf8_string
- Returns true if the first "len" bytes of string "s"
form a valid UTF-8 string, false otherwise. If "len" is 0, it
will be calculated using strlen(s) (which means if you use this option,
that "s" can't have embedded "NUL" characters and has
to have a terminating "NUL" byte). Note that all characters
being ASCII constitute 'a valid UTF-8 string'.
See also "is_ascii_string"(), "is_utf8_string_loclen"(),
and "is_utf8_string_loc"().
bool is_utf8_string(const U8 *s, STRLEN len)
- is_utf8_string_loc
- Like "is_utf8_string" but stores the location of the failure (in
the case of "utf8ness failure") or the location
"s"+"len" (in the case of "utf8ness
success") in the "ep".
See also "is_utf8_string_loclen"() and
"is_utf8_string"().
bool is_utf8_string_loc(const U8 *s, STRLEN len,
const U8 **ep)
- is_utf8_string_loclen
- Like "is_utf8_string"() but stores the location of the failure
(in the case of "utf8ness failure") or the location
"s"+"len" (in the case of "utf8ness
success") in the "ep", and the number of UTF-8 encoded
characters in the "el".
See also "is_utf8_string_loc"() and "is_utf8_string"().
bool is_utf8_string_loclen(const U8 *s, STRLEN len,
const U8 **ep, STRLEN *el)
- pv_uni_display
- Build to the scalar "dsv" a displayable version of the string
"spv", length "len", the displayable version being at
most "pvlim" bytes long (if longer, the rest is truncated and
"..." will be appended).
The "flags" argument can have UNI_DISPLAY_ISPRINT set to display
isPRINT()able characters as themselves, UNI_DISPLAY_BACKSLASH to
display the \\[nrfta\\] as the backslashed versions (like '\n')
(UNI_DISPLAY_BACKSLASH is preferred over UNI_DISPLAY_ISPRINT for \\).
UNI_DISPLAY_QQ (and its alias UNI_DISPLAY_REGEX) have both
UNI_DISPLAY_BACKSLASH and UNI_DISPLAY_ISPRINT turned on.
The pointer to the PV of the "dsv" is returned.
char* pv_uni_display(SV *dsv, const U8 *spv,
STRLEN len, STRLEN pvlim,
UV flags)
- sv_cat_decode
- The encoding is assumed to be an Encode object, the PV of the ssv is
assumed to be octets in that encoding and decoding the input starts from
the position which (PV + *offset) pointed to. The dsv will be concatenated
the decoded UTF-8 string from ssv. Decoding will terminate when the string
tstr appears in decoding output or the input ends on the PV of the ssv.
The value which the offset points will be modified to the last input
position on the ssv.
Returns TRUE if the terminator was found, else returns FALSE.
bool sv_cat_decode(SV* dsv, SV *encoding, SV *ssv,
int *offset, char* tstr, int tlen)
- sv_recode_to_utf8
- The encoding is assumed to be an Encode object, on entry the PV of the sv
is assumed to be octets in that encoding, and the sv will be converted
into Unicode (and UTF-8).
If the sv already is UTF-8 (or if it is not POK), or if the encoding is not
a reference, nothing is done to the sv. If the encoding is not an
"Encode::XS" Encoding object, bad things will happen. (See
lib/encoding.pm and Encode.)
The PV of the sv is returned.
char* sv_recode_to_utf8(SV* sv, SV *encoding)
- sv_uni_display
- Build to the scalar "dsv" a displayable version of the scalar
"sv", the displayable version being at most "pvlim"
bytes long (if longer, the rest is truncated and "..." will be
appended).
The "flags" argument is as in "pv_uni_display"().
The pointer to the PV of the "dsv" is returned.
char* sv_uni_display(SV *dsv, SV *ssv, STRLEN pvlim,
UV flags)
- to_utf8_case
- "p" contains the pointer to the UTF-8 string encoding the
character that is being converted. This routine assumes that the character
at "p" is well-formed.
"ustrp" is a pointer to the character buffer to put the conversion
result to. "lenp" is a pointer to the length of the result.
"swashp" is a pointer to the swash to use.
Both the special and normal mappings are stored in
lib/unicore/To/Foo.pl, and loaded by SWASHNEW, using
lib/utf8_heavy.pl. "special" (usually, but not always, a
multicharacter mapping), is tried first.
"special" is a string, normally "NULL" or "".
"NULL" means to not use any special mappings; "" means
to use the special mappings. Values other than these two are treated as
the name of the hash containing the special mappings, like
"utf8::ToSpecLower".
"normal" is a string like "ToLower" which means the
swash %utf8::ToLower.
UV to_utf8_case(const U8 *p, U8* ustrp,
STRLEN *lenp, SV **swashp,
const char *normal,
const char *special)
- to_utf8_fold
- Instead use "toFOLD_utf8".
UV to_utf8_fold(const U8 *p, U8* ustrp,
STRLEN *lenp)
- to_utf8_lower
- Instead use "toLOWER_utf8".
UV to_utf8_lower(const U8 *p, U8* ustrp,
STRLEN *lenp)
- to_utf8_title
- Instead use "toTITLE_utf8".
UV to_utf8_title(const U8 *p, U8* ustrp,
STRLEN *lenp)
- to_utf8_upper
- Instead use "toUPPER_utf8".
UV to_utf8_upper(const U8 *p, U8* ustrp,
STRLEN *lenp)
- utf8n_to_uvchr
- THIS FUNCTION SHOULD BE USED IN ONLY VERY SPECIALIZED CIRCUMSTANCES. Most
code should use "utf8_to_uvchr_buf"() rather than call this
directly.
Bottom level UTF-8 decode routine. Returns the native code point value of
the first character in the string "s", which is assumed to be in
UTF-8 (or UTF-EBCDIC) encoding, and no longer than "curlen"
bytes; *retlen (if "retlen" isn't NULL) will be set to the
length, in bytes, of that character.
The value of "flags" determines the behavior when "s"
does not point to a well-formed UTF-8 character. If "flags" is
0, when a malformation is found, zero is returned and *retlen is set so
that ("s" + *retlen) is the next possible position
in "s" that could begin a non-malformed character. Also, if
UTF-8 warnings haven't been lexically disabled, a warning is raised.
Various ALLOW flags can be set in "flags" to allow (and not warn
on) individual types of malformations, such as the sequence being overlong
(that is, when there is a shorter sequence that can express the same code
point; overlong sequences are expressly forbidden in the UTF-8 standard
due to potential security issues). Another malformation example is the
first byte of a character not being a legal first byte. See utf8.h
for the list of such flags. For allowed 0 length strings, this function
returns 0; for allowed overlong sequences, the computed code point is
returned; for all other allowed malformations, the Unicode REPLACEMENT
CHARACTER is returned, as these have no determinable reasonable value.
The UTF8_CHECK_ONLY flag overrides the behavior when a non-allowed (by other
flags) malformation is found. If this flag is set, the routine assumes
that the caller will raise a warning, and this function will silently just
set "retlen" to "-1" (cast to "STRLEN") and
return zero.
Note that this API requires disambiguation between successful decoding a
"NUL" character, and an error return (unless the UTF8_CHECK_ONLY
flag is set), as in both cases, 0 is returned. To disambiguate, upon a
zero return, see if the first byte of "s" is 0 as well. If so,
the input was a "NUL"; if not, the input had an error.
Certain code points are considered problematic. These are Unicode
surrogates, Unicode non-characters, and code points above the Unicode
maximum of 0x10FFFF. By default these are considered regular code points,
but certain situations warrant special handling for them. If
"flags" contains UTF8_DISALLOW_ILLEGAL_INTERCHANGE, all three
classes are treated as malformations and handled as such. The flags
UTF8_DISALLOW_SURROGATE, UTF8_DISALLOW_NONCHAR, and UTF8_DISALLOW_SUPER
(meaning above the legal Unicode maximum) can be set to disallow these
categories individually.
The flags UTF8_WARN_ILLEGAL_INTERCHANGE, UTF8_WARN_SURROGATE,
UTF8_WARN_NONCHAR, and UTF8_WARN_SUPER will cause warning messages to be
raised for their respective categories, but otherwise the code points are
considered valid (not malformations). To get a category to both be treated
as a malformation and raise a warning, specify both the WARN and DISALLOW
flags. (But note that warnings are not raised if lexically disabled nor if
UTF8_CHECK_ONLY is also specified.)
Very large code points (above 0x7FFF_FFFF) are considered more problematic
than the others that are above the Unicode legal maximum. There are
several reasons: they requre at least 32 bits to represent them on ASCII
platforms, are not representable at all on EBCDIC platforms, and the
original UTF-8 specification never went above this number (the current
0x10FFFF limit was imposed later). (The smaller ones, those that fit into
32 bits, are representable by a UV on ASCII platforms, but not by an IV,
which means that the number of operations that can be performed on them is
quite restricted.) The UTF-8 encoding on ASCII platforms for these large
code points begins with a byte containing 0xFE or 0xFF. The
UTF8_DISALLOW_FE_FF flag will cause them to be treated as malformations,
while allowing smaller above-Unicode code points. (Of course
UTF8_DISALLOW_SUPER will treat all above-Unicode code points, including
these, as malformations.) Similarly, UTF8_WARN_FE_FF acts just like the
other WARN flags, but applies just to these code points.
All other code points corresponding to Unicode characters, including private
use and those yet to be assigned, are never considered malformed and never
warn.
UV utf8n_to_uvchr(const U8 *s, STRLEN curlen,
STRLEN *retlen, U32 flags)
- utf8n_to_uvuni
- Instead use "utf8_to_uvchr_buf", or rarely,
"utf8n_to_uvchr".
This function was useful for code that wanted to handle both EBCDIC and
ASCII platforms with Unicode properties, but starting in Perl v5.20, the
distinctions between the platforms have mostly been made invisible to most
code, so this function is quite unlikely to be what you want. If you do
need this precise functionality, use instead
"NATIVE_TO_UNI(utf8_to_uvchr_buf(...))" or
"NATIVE_TO_UNI(utf8n_to_uvchr(...))".
UV utf8n_to_uvuni(const U8 *s, STRLEN curlen,
STRLEN *retlen, U32 flags)
- utf8_distance
- Returns the number of UTF-8 characters between the UTF-8 pointers
"a" and "b".
WARNING: use only if you *know* that the pointers point inside the same
UTF-8 buffer.
IV utf8_distance(const U8 *a, const U8 *b)
- utf8_hop
- Return the UTF-8 pointer "s" displaced by "off"
characters, either forward or backward.
WARNING: do not use the following unless you *know* "off" is
within the UTF-8 data pointed to by "s" *and* that on entry
"s" is aligned on the first byte of character or just after the
last byte of a character.
U8* utf8_hop(const U8 *s, I32 off)
- utf8_length
- Return the length of the UTF-8 char encoded string "s" in
characters. Stops at "e" (inclusive). If "e < s" or
if the scan would end up past "e", croaks.
STRLEN utf8_length(const U8* s, const U8 *e)
- utf8_to_bytes
- NOTE: this function is experimental and may change or be removed without
notice.
Converts a string "s" of length "len" from UTF-8 into
native byte encoding. Unlike "bytes_to_utf8", this over-writes
the original string, and updates "len" to contain the new
length. Returns zero on failure, setting "len" to -1.
If you need a copy of the string, see "bytes_from_utf8".
U8* utf8_to_bytes(U8 *s, STRLEN *len)
- utf8_to_uvchr
- DEPRECATED! It is planned to remove this function from a future release of
Perl. Do not use it for new code; remove it from existing code.
Returns the native code point of the first character in the string
"s" which is assumed to be in UTF-8 encoding; "retlen"
will be set to the length, in bytes, of that character.
Some, but not all, UTF-8 malformations are detected, and in fact, some
malformed input could cause reading beyond the end of the input buffer,
which is why this function is deprecated. Use
"utf8_to_uvchr_buf" instead.
If "s" points to one of the detected malformations, and UTF8
warnings are enabled, zero is returned and *retlen is set (if
"retlen" isn't NULL) to -1. If those warnings are off, the
computed value if well-defined (or the Unicode REPLACEMENT CHARACTER, if
not) is silently returned, and *retlen is set (if "retlen" isn't
NULL) so that ("s" + *retlen) is the next possible
position in "s" that could begin a non-malformed character. See
"utf8n_to_uvchr" for details on when the REPLACEMENT CHARACTER
is returned.
UV utf8_to_uvchr(const U8 *s, STRLEN *retlen)
- utf8_to_uvchr_buf
- Returns the native code point of the first character in the string
"s" which is assumed to be in UTF-8 encoding; "send"
points to 1 beyond the end of "s". *retlen will be set to the
length, in bytes, of that character.
If "s" does not point to a well-formed UTF-8 character and UTF8
warnings are enabled, zero is returned and *retlen is set (if
"retlen" isn't NULL) to -1. If those warnings are off, the
computed value, if well-defined (or the Unicode REPLACEMENT CHARACTER if
not), is silently returned, and *retlen is set (if "retlen"
isn't NULL) so that ("s" + *retlen) is the next
possible position in "s" that could begin a non-malformed
character. See "utf8n_to_uvchr" for details on when the
REPLACEMENT CHARACTER is returned.
UV utf8_to_uvchr_buf(const U8 *s, const U8 *send,
STRLEN *retlen)
- utf8_to_uvuni
- DEPRECATED! It is planned to remove this function from a future release of
Perl. Do not use it for new code; remove it from existing code.
Returns the Unicode code point of the first character in the string
"s" which is assumed to be in UTF-8 encoding; "retlen"
will be set to the length, in bytes, of that character.
Some, but not all, UTF-8 malformations are detected, and in fact, some
malformed input could cause reading beyond the end of the input buffer,
which is one reason why this function is deprecated. The other is that
only in extremely limited circumstances should the Unicode versus native
code point be of any interest to you. See "utf8_to_uvuni_buf"
for alternatives.
If "s" points to one of the detected malformations, and UTF8
warnings are enabled, zero is returned and *retlen is set (if
"retlen" doesn't point to NULL) to -1. If those warnings are
off, the computed value if well-defined (or the Unicode REPLACEMENT
CHARACTER, if not) is silently returned, and *retlen is set (if
"retlen" isn't NULL) so that
("s" + *retlen) is the next possible position in
"s" that could begin a non-malformed character. See
"utf8n_to_uvchr" for details on when the REPLACEMENT CHARACTER
is returned.
UV utf8_to_uvuni(const U8 *s, STRLEN *retlen)
- utf8_to_uvuni_buf
- DEPRECATED! It is planned to remove this function from a future release of
Perl. Do not use it for new code; remove it from existing code.
Only in very rare circumstances should code need to be dealing in Unicode
(as opposed to native) code points. In those few cases, use
"NATIVE_TO_UNI(utf8_to_uvchr_buf(...))" instead.
Returns the Unicode (not-native) code point of the first character in the
string "s" which is assumed to be in UTF-8 encoding;
"send" points to 1 beyond the end of "s".
"retlen" will be set to the length, in bytes, of that character.
If "s" does not point to a well-formed UTF-8 character and UTF8
warnings are enabled, zero is returned and *retlen is set (if
"retlen" isn't NULL) to -1. If those warnings are off, the
computed value if well-defined (or the Unicode REPLACEMENT CHARACTER, if
not) is silently returned, and *retlen is set (if "retlen" isn't
NULL) so that ("s" + *retlen) is the next possible
position in "s" that could begin a non-malformed character. See
"utf8n_to_uvchr" for details on when the REPLACEMENT CHARACTER
is returned.
UV utf8_to_uvuni_buf(const U8 *s, const U8 *send,
STRLEN *retlen)
- uvchr_to_utf8
- Adds the UTF-8 representation of the native code point "uv" to
the end of the string "d"; "d" should have at least
"UNISKIP(uv)+1" (up to "UTF8_MAXBYTES+1") free bytes
available. The return value is the pointer to the byte after the end of
the new character. In other words,
d = uvchr_to_utf8(d, uv);
is the recommended wide native character-aware way of saying
*(d++) = uv;
This function accepts any UV as input. To forbid or warn on non-Unicode code
points, or those that may be problematic, see
"uvchr_to_utf8_flags".
U8* uvchr_to_utf8(U8 *d, UV uv)
- uvchr_to_utf8_flags
- Adds the UTF-8 representation of the native code point "uv" to
the end of the string "d"; "d" should have at least
"UNISKIP(uv)+1" (up to "UTF8_MAXBYTES+1") free bytes
available. The return value is the pointer to the byte after the end of
the new character. In other words,
d = uvchr_to_utf8_flags(d, uv, flags);
or, in most cases,
d = uvchr_to_utf8_flags(d, uv, 0);
This is the Unicode-aware way of saying
*(d++) = uv;
This function will convert to UTF-8 (and not warn) even code points that
aren't legal Unicode or are problematic, unless "flags" contains
one or more of the following flags:
If "uv" is a Unicode surrogate code point and
UNICODE_WARN_SURROGATE is set, the function will raise a warning, provided
UTF8 warnings are enabled. If instead UNICODE_DISALLOW_SURROGATE is set,
the function will fail and return NULL. If both flags are set, the
function will both warn and return NULL.
The UNICODE_WARN_NONCHAR and UNICODE_DISALLOW_NONCHAR flags affect how the
function handles a Unicode non-character. And likewise, the
UNICODE_WARN_SUPER and UNICODE_DISALLOW_SUPER flags affect the handling of
code points that are above the Unicode maximum of 0x10FFFF. Code points
above 0x7FFF_FFFF (which are even less portable) can be warned and/or
disallowed even if other above-Unicode code points are accepted, by the
UNICODE_WARN_FE_FF and UNICODE_DISALLOW_FE_FF flags.
And finally, the flag UNICODE_WARN_ILLEGAL_INTERCHANGE selects all four of
the above WARN flags; and UNICODE_DISALLOW_ILLEGAL_INTERCHANGE selects all
four DISALLOW flags.
U8* uvchr_to_utf8_flags(U8 *d, UV uv, UV flags)
- uvoffuni_to_utf8_flags
- THIS FUNCTION SHOULD BE USED IN ONLY VERY SPECIALIZED CIRCUMSTANCES.
Instead, Almost all code should use "uvchr_to_utf8" or
"uvchr_to_utf8_flags".
This function is like them, but the input is a strict Unicode (as opposed to
native) code point. Only in very rare circumstances should code not be
using the native code point.
For details, see the description for "uvchr_to_utf8_flags">.
U8* uvoffuni_to_utf8_flags(U8 *d, UV uv, UV flags)
- uvuni_to_utf8_flags
- Instead you almost certainly want to use "uvchr_to_utf8" or
"uvchr_to_utf8_flags">.
This function is a deprecated synonym for
"uvoffuni_to_utf8_flags", which itself, while not deprecated,
should be used only in isolated circumstances. These functions were useful
for code that wanted to handle both EBCDIC and ASCII platforms with
Unicode properties, but starting in Perl v5.20, the distinctions between
the platforms have mostly been made invisible to most code, so this
function is quite unlikely to be what you want.
U8* uvuni_to_utf8_flags(U8 *d, UV uv, UV flags)
Variables created by "xsubpp" and "xsubpp" internal functions¶
- ax
- Variable which is setup by "xsubpp" to indicate the stack base
offset, used by the "ST", "XSprePUSH" and
"XSRETURN" macros. The "dMARK" macro must be called
prior to setup the "MARK" variable.
I32 ax
- CLASS
- Variable which is setup by "xsubpp" to indicate the class name
for a C++ XS constructor. This is always a "char*". See
"THIS".
char* CLASS
- dAX
- Sets up the "ax" variable. This is usually handled automatically
by "xsubpp" by calling "dXSARGS".
dAX;
- dAXMARK
- Sets up the "ax" variable and stack marker variable
"mark". This is usually handled automatically by
"xsubpp" by calling "dXSARGS".
dAXMARK;
- dITEMS
- Sets up the "items" variable. This is usually handled
automatically by "xsubpp" by calling "dXSARGS".
dITEMS;
- dUNDERBAR
- Sets up any variable needed by the "UNDERBAR" macro. It used to
define "padoff_du", but it is currently a noop. However, it is
strongly advised to still use it for ensuring past and future
compatibility.
dUNDERBAR;
- dXSARGS
- Sets up stack and mark pointers for an XSUB, calling dSP and dMARK. Sets
up the "ax" and "items" variables by calling
"dAX" and "dITEMS". This is usually handled
automatically by "xsubpp".
dXSARGS;
- dXSI32
- Sets up the "ix" variable for an XSUB which has aliases. This is
usually handled automatically by "xsubpp".
dXSI32;
- items
- Variable which is setup by "xsubpp" to indicate the number of
items on the stack. See "Variable-length Parameter Lists" in
perlxs.
I32 items
- ix
- Variable which is setup by "xsubpp" to indicate which of an
XSUB's aliases was used to invoke it. See "The ALIAS: Keyword"
in perlxs.
I32 ix
- newXSproto
- Used by "xsubpp" to hook up XSUBs as Perl subs. Adds Perl
prototypes to the subs.
- RETVAL
- Variable which is setup by "xsubpp" to hold the return value for
an XSUB. This is always the proper type for the XSUB. See "The RETVAL
Variable" in perlxs.
(whatever) RETVAL
- ST
- Used to access elements on the XSUB's stack.
SV* ST(int ix)
- THIS
- Variable which is setup by "xsubpp" to designate the object in a
C++ XSUB. This is always the proper type for the C++ object. See
"CLASS" and "Using XS With C++" in perlxs.
(whatever) THIS
- UNDERBAR
- The SV* corresponding to the $_ variable. Works even if there is a lexical
$_ in scope.
- XS
- Macro to declare an XSUB and its C parameter list. This is handled by
"xsubpp". It is the same as using the more explicit XS_EXTERNAL
macro.
- XS_APIVERSION_BOOTCHECK
- Macro to verify that the perl api version an XS module has been compiled
against matches the api version of the perl interpreter it's being loaded
into.
XS_APIVERSION_BOOTCHECK;
- XS_EXTERNAL
- Macro to declare an XSUB and its C parameter list explicitly exporting the
symbols.
- XS_INTERNAL
- Macro to declare an XSUB and its C parameter list without exporting the
symbols. This is handled by "xsubpp" and generally preferable
over exporting the XSUB symbols unnecessarily.
- XS_VERSION
- The version identifier for an XS module. This is usually handled
automatically by "ExtUtils::MakeMaker". See
"XS_VERSION_BOOTCHECK".
- XS_VERSION_BOOTCHECK
- Macro to verify that a PM module's $VERSION variable matches the XS
module's "XS_VERSION" variable. This is usually handled
automatically by "xsubpp". See "The VERSIONCHECK:
Keyword" in perlxs.
XS_VERSION_BOOTCHECK;
Warning and Dieing¶
- croak
- This is an XS interface to Perl's "die" function.
Take a sprintf-style format pattern and argument list. These are used to
generate a string message. If the message does not end with a newline,
then it will be extended with some indication of the current location in
the code, as described for "mess_sv".
The error message will be used as an exception, by default returning control
to the nearest enclosing "eval", but subject to modification by
a $SIG{__DIE__} handler. In any case, the "croak" function never
returns normally.
For historical reasons, if "pat" is null then the contents of
"ERRSV" ($@) will be used as an error message or object instead
of building an error message from arguments. If you want to throw a
non-string object, or build an error message in an SV yourself, it is
preferable to use the "croak_sv" function, which does not
involve clobbering "ERRSV".
void croak(const char *pat, ...)
- croak_no_modify
- Exactly equivalent to "Perl_croak(aTHX_ "%s",
PL_no_modify)", but generates terser object code than using
"Perl_croak". Less code used on exception code paths reduces CPU
cache pressure.
void croak_no_modify()
- croak_sv
- This is an XS interface to Perl's "die" function.
"baseex" is the error message or object. If it is a reference, it
will be used as-is. Otherwise it is used as a string, and if it does not
end with a newline then it will be extended with some indication of the
current location in the code, as described for "mess_sv".
The error message or object will be used as an exception, by default
returning control to the nearest enclosing "eval", but subject
to modification by a $SIG{__DIE__} handler. In any case, the
"croak_sv" function never returns normally.
To die with a simple string message, the "croak" function may be
more convenient.
void croak_sv(SV *baseex)
- die
- Behaves the same as "croak", except for the return type. It
should be used only where the "OP *" return type is required.
The function never actually returns.
OP * die(const char *pat, ...)
- die_sv
- Behaves the same as "croak_sv", except for the return type. It
should be used only where the "OP *" return type is required.
The function never actually returns.
OP * die_sv(SV *baseex)
- vcroak
- This is an XS interface to Perl's "die" function.
"pat" and "args" are a sprintf-style format pattern and
encapsulated argument list. These are used to generate a string message.
If the message does not end with a newline, then it will be extended with
some indication of the current location in the code, as described for
"mess_sv".
The error message will be used as an exception, by default returning control
to the nearest enclosing "eval", but subject to modification by
a $SIG{__DIE__} handler. In any case, the "croak" function never
returns normally.
For historical reasons, if "pat" is null then the contents of
"ERRSV" ($@) will be used as an error message or object instead
of building an error message from arguments. If you want to throw a
non-string object, or build an error message in an SV yourself, it is
preferable to use the "croak_sv" function, which does not
involve clobbering "ERRSV".
void vcroak(const char *pat, va_list *args)
- vwarn
- This is an XS interface to Perl's "warn" function.
"pat" and "args" are a sprintf-style format pattern and
encapsulated argument list. These are used to generate a string message.
If the message does not end with a newline, then it will be extended with
some indication of the current location in the code, as described for
"mess_sv".
The error message or object will by default be written to standard error,
but this is subject to modification by a $SIG{__WARN__} handler.
Unlike with "vcroak", "pat" is not permitted to be null.
void vwarn(const char *pat, va_list *args)
- warn
- This is an XS interface to Perl's "warn" function.
Take a sprintf-style format pattern and argument list. These are used to
generate a string message. If the message does not end with a newline,
then it will be extended with some indication of the current location in
the code, as described for "mess_sv".
The error message or object will by default be written to standard error,
but this is subject to modification by a $SIG{__WARN__} handler.
Unlike with "croak", "pat" is not permitted to be null.
void warn(const char *pat, ...)
- warn_sv
- This is an XS interface to Perl's "warn" function.
"baseex" is the error message or object. If it is a reference, it
will be used as-is. Otherwise it is used as a string, and if it does not
end with a newline then it will be extended with some indication of the
current location in the code, as described for "mess_sv".
The error message or object will by default be written to standard error,
but this is subject to modification by a $SIG{__WARN__} handler.
To warn with a simple string message, the "warn" function may be
more convenient.
void warn_sv(SV *baseex)
Undocumented functions¶
The following functions have been flagged as part of the public API, but are
currently undocumented. Use them at your own risk, as the interfaces are
subject to change. Functions that are not listed in this document are not
intended for public use, and should NOT be used under any circumstances.
If you use one of the undocumented functions below, you may wish to consider
creating and submitting documentation for it. If your patch is accepted, this
will indicate that the interface is stable (unless it is explicitly marked
otherwise).
- GetVars
- Gv_AMupdate
- PerlIO_clearerr
- PerlIO_close
- PerlIO_context_layers
- PerlIO_eof
- PerlIO_error
- PerlIO_fileno
- PerlIO_fill
- PerlIO_flush
- PerlIO_get_base
- PerlIO_get_bufsiz
- PerlIO_get_cnt
- PerlIO_get_ptr
- PerlIO_read
- PerlIO_seek
- PerlIO_set_cnt
- PerlIO_set_ptrcnt
- PerlIO_setlinebuf
- PerlIO_stderr
- PerlIO_stdin
- PerlIO_stdout
- PerlIO_tell
- PerlIO_unread
- PerlIO_write
- amagic_call
- amagic_deref_call
- any_dup
- atfork_lock
- atfork_unlock
- av_arylen_p
- av_iter_p
- block_gimme
- call_atexit
- call_list
- calloc
- cast_i32
- cast_iv
- cast_ulong
- cast_uv
- ck_warner
- ck_warner_d
- ckwarn
- ckwarn_d
- clone_params_del
- clone_params_new
- croak_memory_wrap
- croak_nocontext
- csighandler
- cx_dump
- cx_dup
- cxinc
- deb
- deb_nocontext
- debop
- debprofdump
- debstack
- debstackptrs
- delimcpy
- despatch_signals
- die_nocontext
- dirp_dup
- do_aspawn
- do_binmode
- do_close
- do_gv_dump
- do_gvgv_dump
- do_hv_dump
- do_join
- do_magic_dump
- do_op_dump
- do_open
- do_open9
- do_openn
- do_pmop_dump
- do_spawn
- do_spawn_nowait
- do_sprintf
- do_sv_dump
- doing_taint
- doref
- dounwind
- dowantarray
- dump_eval
- dump_form
- dump_indent
- dump_mstats
- dump_sub
- dump_vindent
- filter_add
- filter_del
- filter_read
- foldEQ_latin1
- form_nocontext
- fp_dup
- fprintf_nocontext
- free_global_struct
- free_tmps
- get_context
- get_mstats
- get_op_descs
- get_op_names
- get_ppaddr
- get_vtbl
- gp_dup
- gp_free
- gp_ref
- gv_AVadd
- gv_HVadd
- gv_IOadd
- gv_SVadd
- gv_add_by_type
- gv_autoload4
- gv_autoload_pv
- gv_autoload_pvn
- gv_autoload_sv
- gv_check
- gv_dump
- gv_efullname
- gv_efullname3
- gv_efullname4
- gv_fetchfile
- gv_fetchfile_flags
- gv_fetchpv
- gv_fetchpvn_flags
- gv_fetchsv
- gv_fullname
- gv_fullname3
- gv_fullname4
- gv_handler
- gv_name_set
- he_dup
- hek_dup
- hv_common
- hv_common_key_len
- hv_delayfree_ent
- hv_eiter_p
- hv_eiter_set
- hv_free_ent
- hv_ksplit
- hv_name_set
- hv_placeholders_get
- hv_placeholders_set
- hv_rand_set
- hv_riter_p
- hv_riter_set
- init_global_struct
- init_stacks
- init_tm
- instr
- is_lvalue_sub
- leave_scope
- load_module_nocontext
- magic_dump
- malloc
- markstack_grow
- mess_nocontext
- mfree
- mg_dup
- mg_size
- mini_mktime
- moreswitches
- mro_get_from_name
- mro_get_private_data
- mro_set_mro
- mro_set_private_data
- my_atof
- my_atof2
- my_bcopy
- my_bzero
- my_chsize
- my_cxt_index
- my_cxt_init
- my_dirfd
- my_exit
- my_failure_exit
- my_fflush_all
- my_fork
- my_lstat
- my_memcmp
- my_memset
- my_pclose
- my_popen
- my_popen_list
- my_setenv
- my_socketpair
- my_stat
- my_strftime
- newANONATTRSUB
- newANONHASH
- newANONLIST
- newANONSUB
- newATTRSUB
- newAVREF
- newCVREF
- newFORM
- newGVREF
- newGVgen
- newGVgen_flags
- newHVREF
- newHVhv
- newIO
- newMYSUB
- newPROG
- newRV
- newSUB
- newSVREF
- newSVpvf_nocontext
- new_stackinfo
- ninstr
- op_refcnt_lock
- op_refcnt_unlock
- parser_dup
- perl_alloc_using
- perl_clone_using
- pmop_dump
- pop_scope
- pregcomp
- pregexec
- pregfree
- pregfree2
- printf_nocontext
- ptr_table_fetch
- ptr_table_free
- ptr_table_new
- ptr_table_split
- ptr_table_store
- push_scope
- re_compile
- re_dup_guts
- re_intuit_start
- re_intuit_string
- realloc
- reentrant_free
- reentrant_init
- reentrant_retry
- reentrant_size
- ref
- reg_named_buff_all
- reg_named_buff_exists
- reg_named_buff_fetch
- reg_named_buff_firstkey
- reg_named_buff_nextkey
- reg_named_buff_scalar
- regclass_swash
- regdump
- regdupe_internal
- regexec_flags
- regfree_internal
- reginitcolors
- regnext
- repeatcpy
- rninstr
- rsignal
- rsignal_state
- runops_debug
- runops_standard
- rvpv_dup
- safesyscalloc
- safesysfree
- safesysmalloc
- safesysrealloc
- save_I16
- save_I32
- save_I8
- save_adelete
- save_aelem
- save_aelem_flags
- save_alloc
- save_aptr
- save_ary
- save_bool
- save_clearsv
- save_delete
- save_destructor
- save_destructor_x
- save_freeop
- save_freepv
- save_freesv
- save_generic_pvref
- save_generic_svref
- save_gp
- save_hash
- save_hdelete
- save_helem
- save_helem_flags
- save_hints
- save_hptr
- save_int
- save_item
- save_iv
- save_list
- save_long
- save_mortalizesv
- save_nogv
- save_op
- save_padsv_and_mortalize
- save_pptr
- save_pushi32ptr
- save_pushptr
- save_pushptrptr
- save_re_context
- save_scalar
- save_set_svflags
- save_shared_pvref
- save_sptr
- save_svref
- save_vptr
- savestack_grow
- savestack_grow_cnt
- scan_num
- scan_vstring
- screaminstr
- seed
- set_context
- set_numeric_local
- set_numeric_radix
- set_numeric_standard
- share_hek
- si_dup
- ss_dup
- stack_grow
- start_subparse
- str_to_version
- sv_2iv
- sv_2pv
- sv_2uv
- sv_catpvf_mg_nocontext
- sv_catpvf_nocontext
- sv_dup
- sv_dup_inc
- sv_peek
- sv_pvn_nomg
- sv_setpvf_mg_nocontext
- sv_setpvf_nocontext
- swash_fetch
- swash_init
- sys_init
- sys_init3
- sys_intern_clear
- sys_intern_dup
- sys_intern_init
- sys_term
- taint_env
- taint_proper
- tmps_grow
- unlnk
- unsharepvn
- utf16_to_utf8
- utf16_to_utf8_reversed
- uvuni_to_utf8
- vdeb
- vform
- vload_module
- vnewSVpvf
- vwarner
- warn_nocontext
- warner
- warner_nocontext
- whichsig
- whichsig_pv
- whichsig_pvn
- whichsig_sv
AUTHORS¶
Until May 1997, this document was maintained by Jeff Okamoto
<okamoto@corp.hp.com>. It is now maintained as part of Perl itself.
With lots of help and suggestions from Dean Roehrich, Malcolm Beattie, Andreas
Koenig, Paul Hudson, Ilya Zakharevich, Paul Marquess, Neil Bowers, Matthew
Green, Tim Bunce, Spider Boardman, Ulrich Pfeifer, Stephen McCamant, and
Gurusamy Sarathy.
API Listing originally by Dean Roehrich <roehrich@cray.com>.
Updated to be autogenerated from comments in the source by Benjamin Stuhl.
SEE ALSO¶
perlguts, perlxs, perlxstut, perlintern