NAME¶
Tcl_UniChar, Tcl_UniCharCaseMatch, Tcl_UniCharNcasecmp, Tcl_UniCharToUtf,
Tcl_UtfToUniChar, Tcl_UniCharToUtfDString, Tcl_UtfToUniCharDString,
Tcl_UniCharLen, Tcl_UniCharNcmp, Tcl_UtfCharComplete, Tcl_NumUtfChars,
Tcl_UtfFindFirst, Tcl_UtfFindLast, Tcl_UtfNext, Tcl_UtfPrev,
Tcl_UniCharAtIndex, Tcl_UtfAtIndex, Tcl_UtfBackslash - routines for
manipulating UTF-8 strings
SYNOPSIS¶
#include <tcl.h>
typedef ... Tcl_UniChar;
int
Tcl_UniCharToUtf(ch, buf)
int
Tcl_UtfToUniChar(src, chPtr)
char *
Tcl_UniCharToUtfDString(uniStr, uniLength, dsPtr)
Tcl_UniChar *
Tcl_UtfToUniCharDString(src, length, dsPtr)
int
Tcl_UniCharLen(uniStr)
int
Tcl_UniCharNcmp(ucs, uct, numChars)
int
Tcl_UniCharNcasecmp(ucs, uct, numChars)
int
Tcl_UniCharCaseMatch(uniStr, uniPattern, nocase)
int
Tcl_UtfNcmp(cs, ct, numChars)
int
Tcl_UtfNcasecmp(cs, ct, numChars)
int
Tcl_UtfCharComplete(src, length)
int
Tcl_NumUtfChars(src, length)
const char *
Tcl_UtfFindFirst(src, ch)
const char *
Tcl_UtfFindLast(src, ch)
const char *
Tcl_UtfNext(src)
const char *
Tcl_UtfPrev(src, start)
Tcl_UniChar
Tcl_UniCharAtIndex(src, index)
const char *
Tcl_UtfAtIndex(src, index)
int
Tcl_UtfBackslash(src, readPtr, dst)
ARGUMENTS¶
- char *buf (out)
- Buffer in which the UTF-8 representation of the Tcl_UniChar is stored. At
most TCL_UTF_MAX bytes are stored in the buffer.
- int ch (in)
- The Tcl_UniChar to be converted or examined.
- Tcl_UniChar *chPtr (out)
- Filled with the Tcl_UniChar represented by the head of the UTF-8
string.
- const char *src (in)
- Pointer to a UTF-8 string.
- const char *cs (in)
- Pointer to a UTF-8 string.
- const char *ct (in)
- Pointer to a UTF-8 string.
- const Tcl_UniChar *uniStr (in)
- A null-terminated Unicode string.
- const Tcl_UniChar *ucs (in)
- A null-terminated Unicode string.
- const Tcl_UniChar *uct (in)
- A null-terminated Unicode string.
- const Tcl_UniChar *uniPattern (in)
- A null-terminated Unicode string.
- int length (in)
- The length of the UTF-8 string in bytes (not UTF-8 characters). If
negative, all bytes up to the first null byte are used.
- int uniLength (in)
- The length of the Unicode string in characters. Must be greater than or
equal to 0.
- Tcl_DString *dsPtr (in/out)
- A pointer to a previously initialized Tcl_DString.
- unsigned long numChars (in)
- The number of characters to compare.
- const char *start (in)
- Pointer to the beginning of a UTF-8 string.
- int index (in)
- The index of a character (not byte) in the UTF-8 string.
- int *readPtr (out)
- If non-NULL, filled with the number of bytes in the backslash sequence,
including the backslash character.
- char *dst (out)
- Buffer in which the bytes represented by the backslash sequence are
stored. At most TCL_UTF_MAX bytes are stored in the buffer.
- int nocase (in)
- Specifies whether the match should be done case-sensitive (0) or
case-insensitive (1).
DESCRIPTION¶
These routines convert between UTF-8 strings and Tcl_UniChars. A Tcl_UniChar is
a Unicode character represented as an unsigned, fixed-size quantity. A UTF-8
character is a Unicode character represented as a varying-length sequence of
up to
TCL_UTF_MAX bytes. A multibyte UTF-8 sequence consists of a lead
byte followed by some number of trail bytes.
TCL_UTF_MAX is the maximum number of bytes that it takes to represent one
Unicode character in the UTF-8 representation.
Tcl_UniCharToUtf stores the Tcl_UniChar
ch as a UTF-8 string in
starting at
buf. The return value is the number of bytes stored in
buf.
Tcl_UtfToUniChar reads one UTF-8 character starting at
src and
stores it as a Tcl_UniChar in
*chPtr. The return value is the number of
bytes read from
src. The caller must ensure that the source buffer is
long enough such that this routine does not run off the end and dereference
non-existent or random memory; if the source buffer is known to be
null-terminated, this will not happen. If the input is not in proper UTF-8
format,
Tcl_UtfToUniChar will store the first byte of
src in
*chPtr as a Tcl_UniChar between 0x0000 and 0x00ff and return 1.
Tcl_UniCharToUtfDString converts the given Unicode string to UTF-8,
storing the result in a previously initialized
Tcl_DString. You must
specify
uniLength, the length of the given Unicode string. The return
value is a pointer to the UTF-8 representation of the Unicode string. Storage
for the return value is appended to the end of the
Tcl_DString.
Tcl_UtfToUniCharDString converts the given UTF-8 string to Unicode,
storing the result in the previously initialized
Tcl_DString. In the
argument
length, you may either specify the length of the given UTF-8
string in bytes or “-1”, in which case
Tcl_UtfToUniCharDString uses
strlen to calculate the length. The
return value is a pointer to the Unicode representation of the UTF-8 string.
Storage for the return value is appended to the end of the
Tcl_DString.
The Unicode string is terminated with a Unicode null character.
Tcl_UniCharLen corresponds to
strlen for Unicode characters. It
accepts a null-terminated Unicode string and returns the number of Unicode
characters (not bytes) in that string.
Tcl_UniCharNcmp and
Tcl_UniCharNcasecmp correspond to
strncmp and
strncasecmp, respectively, for Unicode characters.
They accept two null-terminated Unicode strings and the number of characters
to compare. Both strings are assumed to be at least
numChars characters
long.
Tcl_UniCharNcmp compares the two strings character-by-character
according to the Unicode character ordering. It returns an integer greater
than, equal to, or less than 0 if the first string is greater than, equal to,
or less than the second string respectively.
Tcl_UniCharNcasecmp is the
Unicode case insensitive version.
Tcl_UniCharCaseMatch is the Unicode equivalent to
Tcl_StringCaseMatch. It accepts a null-terminated Unicode string, a
Unicode pattern, and a boolean value specifying whether the match should be
case sensitive and returns whether the string matches the pattern.
Tcl_UtfNcmp corresponds to
strncmp for UTF-8 strings. It accepts
two null-terminated UTF-8 strings and the number of characters to compare.
(Both strings are assumed to be at least
numChars characters long.)
Tcl_UtfNcmp compares the two strings character-by-character according
to the Unicode character ordering. It returns an integer greater than, equal
to, or less than 0 if the first string is greater than, equal to, or less than
the second string respectively.
Tcl_UtfNcasecmp corresponds to
strncasecmp for UTF-8 strings. It
is similar to
Tcl_UtfNcmp except comparisons ignore differences in case
when comparing upper, lower or title case characters.
Tcl_UtfCharComplete returns 1 if the source UTF-8 string
src of
length bytes is long enough to be decoded by
Tcl_UtfToUniChar,
or 0 otherwise. This function does not guarantee that the UTF-8 string is
properly formed. This routine is used by procedures that are operating on a
byte at a time and need to know if a full Tcl_UniChar has been seen.
Tcl_NumUtfChars corresponds to
strlen for UTF-8 strings. It
returns the number of Tcl_UniChars that are represented by the UTF-8 string
src. The length of the source string is
length bytes. If the
length is negative, all bytes up to the first null byte are used.
Tcl_UtfFindFirst corresponds to
strchr for UTF-8 strings. It
returns a pointer to the first occurrence of the Tcl_UniChar
ch in the
null-terminated UTF-8 string
src. The null terminator is considered
part of the UTF-8 string.
Tcl_UtfFindLast corresponds to
strrchr for UTF-8 strings. It
returns a pointer to the last occurrence of the Tcl_UniChar
ch in the
null-terminated UTF-8 string
src. The null terminator is considered
part of the UTF-8 string.
Given
src, a pointer to some location in a UTF-8 string,
Tcl_UtfNext returns a pointer to the next UTF-8 character in the
string. The caller must not ask for the next character after the last
character in the string if the string is not terminated by a null character.
Given
src, a pointer to some location in a UTF-8 string (or to a null
byte immediately following such a string),
Tcl_UtfPrev returns a
pointer to the closest preceding byte that starts a UTF-8 character. This
function will not back up to a position before
start, the start of the
UTF-8 string. If
src was already at
start, the return value will
be
start.
Tcl_UniCharAtIndex corresponds to a C string array dereference or the
Pascal Ord() function. It returns the Tcl_UniChar represented at the specified
character (not byte)
index in the UTF-8 string
src. The source
string must contain at least
index characters. Behavior is undefined if
a negative
index is given.
Tcl_UtfAtIndex returns a pointer to the specified character (not byte)
index in the UTF-8 string
src. The source string must contain at
least
index characters. This is equivalent to calling
Tcl_UtfNext index times. If a negative
index is given,
the return pointer points to the first character in the source string.
Tcl_UtfBackslash is a utility procedure used by several of the Tcl
commands. It parses a backslash sequence and stores the properly formed UTF-8
character represented by the backslash sequence in the output buffer
dst. At most
TCL_UTF_MAX bytes are stored in the buffer.
Tcl_UtfBackslash modifies
*readPtr to contain the number of
bytes in the backslash sequence, including the backslash character. The return
value is the number of bytes stored in the output buffer.
See the
Tcl manual entry for information on the valid backslash
sequences. All of the sequences described in the Tcl manual entry are
supported by
Tcl_UtfBackslash.
KEYWORDS¶
utf, unicode, backslash