pod::checker(3)

NAME

Pod::Checker, podchecker() - check pod documents for syn
tax errors

SYNOPSIS

use Pod::Checker;
$syntax_okay = podchecker($filepath,  $outputpath,  %options);
my $checker = new Pod::Checker %options;
$checker->parse_from_file($filepath, TDERR);

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 refer
ence to an open filehandle. If unspecified, the inputfile it defaults to "TDIN", and the output-file
defaults to "TDERR".

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 "Warn
ings".

DESCRIPTION

podchecker will perform syntax checking of Perl5 POD for mat documentation.

NOTE THAT THIS MODULE IS CURRENTLY IN THE BETA STAGE!

It is hoped that curious/ambitious user will help flesh
out and add the 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 preformed:

· Unknown '=xxxx' commands, unknown 'X<...>' inte

rior-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 whites
pace.

· Spurious text after =pod / =cut

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

· 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.

· 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 con
tinued with a numbered one. This is obviously incon
sistent. 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 misinter
preted 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 imme
diately 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.

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<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 delim
iter in case of doubt, one ought to escape these lit
eral 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

[T.B.D.]

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 fea
ture 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 con
versions.

"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 rec
ognized:

"-warnings => num"

Print warnings if "num" is true. The higher the

value of "num", the more warnings are printed. Cur
rently 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 follow
ing options are recognized and used to form the out
put:

-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->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 occur
rence. 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 hyper
links (as defined by "L<>") of the current POD. They
consist of a 2-item array: line number and
"Pod::Hyperlink" object.

AUTHOR

Brad Appleton <bradapp@enteract.com> (initial version),
Marek Rouchal <marek@saftsack.fs.uni-bayreuth.de>

Based on code for PPoodd::::TTeexxtt::::ppoodd22tteexxtt(()) written by Tom

Christiansen <tchrist@mox.perl.com>