


Pod::Checker(3p) Perl Programmers Reference GuidePod::Checker(3p)


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:

       o   Unknown '=xxxx' commands, unknown 'X<...>' interior-
           sequences, and unterminated interior sequences.

       o   Check for proper balancing of "=begin" and "=end". The
           contents of such a block are generally ignored, i.e.
           no syntax checks are performed.

       o   Check for proper nesting and balancing of "=over",
           "=item" and "=back".

       o   Check for same nested interior-sequences (e.g.
           "L<...L<...>...>").

       o   Check for malformed or non-existing entities "E<...>".

       o   Check for correct syntax of hyperlinks "L<...>". See



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           perlpod for details.

       o   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
       o   empty =headn

           A heading ("=head1" or "=head2") without any text?
           That ain't no heading!

       o   =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.

       o   =item without previous =over

       o   =back without previous =over

           An "=item" or "=back" command has been found outside a
           "=over"/"=back" block.

       o   No argument for =begin

           A "=begin" command was found that is not followed by
           the formatter specification.

       o   =end without =begin

           A standalone "=end" command was found.

       o   Nested =begin's

           There were at least two consecutive "=begin" commands
           without the corresponding "=end". Only one "=begin"
           may be active at a time.

       o   =for without formatter specification

           There is no specification of the formatter after the
           "=for" command.

       o   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 "".

       o   Unknown command "CMD"




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           An invalid POD command has been found. Valid are
           "=head1", "=head2", "=head3", "=head4", "=over",
           "=item", "=back", "=begin", "=end", "=for", "=pod",
           "=cut"

       o   Unknown interior-sequence "SEQ"

           An invalid markup command has been encountered. Valid
           are: "B<>", "C<>", "E<>", "F<>", "I<>", "L<>", "S<>",
           "X<>", "Z<>"

       o   nested commands CMD<...CMD<...>...>

           Two nested identical markup commands have been found.
           Generally this does not make sense.

       o   garbled entity STRING

           The STRING found cannot be interpreted as a character
           entity.

       o   Entity number out of range

           An entity specified by number (dec, hex, oct) is out
           of range (1-255).

       o   malformed link L<>

           The link found cannot be parsed because it does not
           conform to the syntax described in perlpod.

       o   nonempty Z<>

           The "Z<>" sequence is supposed to be empty.

       o   empty X<>

           The index entry specified contains nothing but
           whitespace.

       o   Spurious text after =pod / =cut

           The commands "=pod" and "=cut" do not take any
           arguments.

       o   Spurious character(s) after =back

           The "=back" command does not take any arguments.

   Warnings
       These may not necessarily cause trouble, but indicate
       mediocre style.

       o   multiple occurrence of link target name



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           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.

       o   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.

       o   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.

       o   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.

       o   =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.

       o   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.

       o   Unknown entity

           A character entity was found that does not belong to
           the standard ISO set or the POD specials "verbar" and
           "sol".

       o   No items in =over

           The list opened with "=over" does not contain any
           items.

       o   No argument for =item

           "=item" without any parameters is deprecated. It
           should either be followed by "*" to indicate an



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           unordered list, by a number (optionally followed by a
           dot) to indicate an ordered (numbered) list or simple
           text for a definition list.

       o   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.

       o   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.

       o   =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:

       o   ignoring leading/trailing whitespace in link

           There is whitespace at the beginning or the end of the
           contents of L<...>.

       o   (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 ().

       o   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



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       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.




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             -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>










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