• NAME
• SYNOPSIS
• OPTIONS/ARGUMENTS
• podchecker()
• DESCRIPTION
• DIAGNOSTICS
• Errors
• Warnings
• Hyperlinks
• RETURN VALUE
• EXAMPLES
• INTERFACE
• AUTHOR

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 the perlpod manpage.

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 the perlpod manpage 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 the perlpod manpage.
• 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 =items. 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>