NAME¶
Pod::Checker, podchecker() - check pod documents for syntax errors
SYNOPSIS¶
use Pod::Checker;
$syntax_okay = podchecker($filepath, $outputpath, %options);
my $checker = new Pod::Checker %options;
$checker->parse_from_file($filepath, \*STDERR);
OPTIONS/ARGUMENTS¶
$filepath is the input POD to read and $outputpath is where to write POD syntax
error messages. Either argument may be a scalar indicating a file-path, or
else a reference to an open filehandle. If unspecified, the input-file it
defaults to "\*STDIN", and the output-file defaults to
"\*STDERR".
podchecker()¶
This function can take a hash of options:
- -warnings => val
- Turn warnings on/off. val is usually 1 for on, but
higher values trigger additional warnings. See "Warnings".
DESCRIPTION¶
podchecker will perform syntax checking of Perl5 POD format
documentation.
Curious/ambitious users are welcome to propose additional features they wish to
see in
Pod::Checker and
podchecker and verify that the checks
are consistent with perlpod.
The following checks are currently performed:
- •
- Unknown '=xxxx' commands, unknown 'X<...>'
interior-sequences, and unterminated interior sequences.
- •
- Check for proper balancing of "=begin" and
"=end". The contents of such a block are generally ignored, i.e.
no syntax checks are performed.
- •
- Check for proper nesting and balancing of
"=over", "=item" and "=back".
- •
- Check for same nested interior-sequences (e.g.
"L<...L<...>...>").
- •
- Check for malformed or non-existing entities
"E<...>".
- •
- Check for correct syntax of hyperlinks
"L<...>". See perlpod for details.
- •
- Check for unresolved document-internal links. This check
may also reveal misspelled links that seem to be internal links but should
be links to something else.
DIAGNOSTICS¶
Errors¶
- •
- empty =headn
A heading ("=head1" or "=head2") without any text? That
ain't no heading!
- •
- =over on line N without closing =back
The "=over" command does not have a corresponding
"=back" before the next heading ("=head1" or
"=head2") or the end of the file.
- •
- =item without previous =over
- •
- =back without previous =over
An "=item" or "=back" command has been found outside a
"=over"/"=back" block.
- •
- No argument for =begin
A "=begin" command was found that is not followed by the formatter
specification.
- •
- =end without =begin
A standalone "=end" command was found.
- •
- Nested =begin's
There were at least two consecutive "=begin" commands without the
corresponding "=end". Only one "=begin" may be active
at a time.
- •
- =for without formatter specification
There is no specification of the formatter after the "=for"
command.
- •
- unresolved internal link NAME
The given link to NAME does not have a matching node in the current
POD. This also happened when a single word node name is not enclosed in
"".
- •
- Unknown command "CMD"
An invalid POD command has been found. Valid are "=head1",
"=head2", "=head3", "=head4",
"=over", "=item", "=back",
"=begin", "=end", "=for", "=pod",
"=cut"
- •
- Unknown interior-sequence "SEQ"
An invalid markup command has been encountered. Valid are:
"B<>", "C<>", "E<>",
"F<>", "I<>", "L<>",
"S<>", "X<>", "Z<>"
- •
- nested commands
CMD<...CMD<...>...>
Two nested identical markup commands have been found. Generally this does
not make sense.
- •
- garbled entity STRING
The STRING found cannot be interpreted as a character entity.
- •
- Entity number out of range
An entity specified by number (dec, hex, oct) is out of range (1-255).
- •
- malformed link L<>
The link found cannot be parsed because it does not conform to the syntax
described in perlpod.
- •
- nonempty Z<>
The "Z<>" sequence is supposed to be empty.
- •
- empty X<>
The index entry specified contains nothing but whitespace.
- •
- Spurious text after =pod / =cut
The commands "=pod" and "=cut" do not take any
arguments.
- •
- Spurious character(s) after =back
The "=back" command does not take any arguments.
Warnings¶
These may not necessarily cause trouble, but indicate mediocre style.
- •
- multiple occurrence of link target name
The POD file has some "=item" and/or "=head" commands
that have the same text. Potential hyperlinks to such a text cannot be
unique then. This warning is printed only with warning level greater than
one.
- •
- line containing nothing but whitespace in paragraph
There is some whitespace on a seemingly empty line. POD is very sensitive to
such things, so this is flagged. vi users switch on the list
option to avoid this problem.
- •
- previous =item has no contents
There is a list "=item" right above the flagged line that has no
text contents. You probably want to delete empty items.
- •
- preceding non-item paragraph(s)
A list introduced by "=over" starts with a text or verbatim
paragraph, but continues with "=item"s. Move the non-item
paragraph out of the "=over"/"=back" block.
- •
- =item type mismatch (one vs. two)
A list started with e.g. a bullet-like "=item" and continued with
a numbered one. This is obviously inconsistent. For most translators the
type of the first "=item" determines the type of the
list.
- •
- N unescaped "<>" in paragraph
Angle brackets not written as "<lt>" and
"<gt>" can potentially cause errors as they could be
misinterpreted as markup commands. This is only printed when the -warnings
level is greater than 1.
- •
- Unknown entity
A character entity was found that does not belong to the standard ISO set or
the POD specials "verbar" and "sol".
- •
- No items in =over
The list opened with "=over" does not contain any items.
- •
- No argument for =item
"=item" without any parameters is deprecated. It should either be
followed by "*" to indicate an unordered list, by a number
(optionally followed by a dot) to indicate an ordered (numbered) list or
simple text for a definition list.
- •
- empty section in previous paragraph
The previous section (introduced by a "=head" command) does not
contain any text. This usually indicates that something is missing. Note:
A "=head1" followed immediately by "=head2" does not
trigger this warning.
- •
- Verbatim paragraph in NAME section
The NAME section ("=head1 NAME") should consist of a single
paragraph with the script/module name, followed by a dash `-' and a very
short description of what the thing is good for.
- •
- =headn without preceding higher level
For example if there is a "=head2" in the POD file prior to a
"=head1".
Hyperlinks¶
There are some warnings with respect to malformed hyperlinks:
- •
- ignoring leading/trailing whitespace in link
There is whitespace at the beginning or the end of the contents of
L<...>.
- •
- (section) in '$page' deprecated
There is a section detected in the page name of L<...>, e.g.
"L<passwd(2)>". POD hyperlinks may point to POD documents
only. Please write "C<passwd(2)>" instead. Some formatters
are able to expand this to appropriate code. For links to (builtin)
functions, please say "L<perlfunc/mkdir>", without
().
- •
- alternative text/node '%s' contains non-escaped | or /
The characters "|" and "/" are special in the
L<...> context. Although the hyperlink parser does its best to
determine which "/" is text and which is a delimiter in case of
doubt, one ought to escape these literal characters like this:
/ E<sol>
| E<verbar>
RETURN VALUE¶
podchecker returns the number of POD syntax errors found or -1 if there
were no POD commands at all found in the file.
EXAMPLES¶
See "SYNOPSIS"
INTERFACE¶
While checking, this module collects document properties, e.g. the nodes for
hyperlinks ("=headX", "=item") and index entries
("X<>"). POD translators can use this feature to syntax-check
and get the nodes in a first pass before actually starting to convert. This is
expensive in terms of execution time, but allows for very robust conversions.
Since PodParser-1.24 the
Pod::Checker module uses only the
poderror method to print errors and warnings. The summary output (e.g.
"Pod syntax OK") has been dropped from the module and has been
included in
podchecker (the script). This allows users of
Pod::Checker to control completely the output behavior. Users of
podchecker (the script) get the well-known behavior.
- "Pod::Checker->new( %options )"
- Return a reference to a new Pod::Checker object that
inherits from Pod::Parser and is used for calling the required methods
later. The following options are recognized:
"-warnings => num"
Print warnings if "num" is true. The higher the value of
"num", the more warnings are printed. Currently there are only
levels 1 and 2.
"-quiet => num"
If "num" is true, do not print any errors/warnings. This is
useful when Pod::Checker is used to munge POD code into plain text from
within POD formatters.
- "$checker->poderror( @args )"
- "$checker->poderror( {%opts}, @args )"
- Internal method for printing errors and warnings. If no
options are given, simply prints "@_". The following options are
recognized and used to form the output:
-msg
A message to print prior to @args.
-line
The line number the error occurred in.
-file
The file (name) the error occurred in.
-severity
The error level, should be 'WARNING' or 'ERROR'.
- "$checker->num_errors()"
- Set (if argument specified) and retrieve the number of
errors found.
- "$checker->num_warnings()"
- Set (if argument specified) and retrieve the number of
warnings found.
- "$checker->name()"
- Set (if argument specified) and retrieve the canonical name
of POD as found in the "=head1 NAME" section.
- "$checker->node()"
- Add (if argument specified) and retrieve the nodes (as
defined by "=headX" and "=item") of the current POD.
The nodes are returned in the order of their occurrence. They consist of
plain text, each piece of whitespace is collapsed to a single blank.
- "$checker->idx()"
- Add (if argument specified) and retrieve the index entries
(as defined by "X<>") of the current POD. They consist of
plain text, each piece of whitespace is collapsed to a single blank.
- "$checker->hyperlink()"
- Add (if argument specified) and retrieve the hyperlinks (as
defined by "L<>") of the current POD. They consist of a
2-item array: line number and "Pod::Hyperlink" object.
AUTHOR¶
Please report bugs using <
http://rt.cpan.org>.
Brad Appleton <bradapp@enteract.com> (initial version), Marek Rouchal
<marekr@cpan.org>
Based on code for
Pod::Text::pod2text() written by
Tom Christiansen <tchrist@mox.perl.com>