Pod::Checker(3pm) Perl Programmers Reference Guide Pod::Checker(3pm)
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 nonexisting 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 happend 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 hyper-links hyperlinks
links 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 bulletted "=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 wrt. 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<perl-
func/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 warn-ings. warnings.
ings. 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 out-put output
put behaviour. Users of podchecker (the script) get the well-known behaviour.
"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 Pd:et:o2et) written by Tom Christiansen <tchrist@mox.perl.com>
perl v5.8.8 2001-09-21 Pod::Checker(3pm)
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