Pod::Checker, podchecker() - check pod documents for syntax errors
$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
.
This function can take a hash of options:
Turn warnings on/off. val is usually 1 for on, but higher values trigger additional warnings. See Warnings.
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.
A heading (=head1
or =head2
) without any text? That ain't no
heading!
The =over
command does not have a corresponding =back
before the
next heading (=head1
or =head2
) or the end of the file.
An =item
or =back
command has been found outside a
=over
/=back
block.
A =begin
command was found that is not followed by the formatter
specification.
A standalone =end
command was found.
There were at least two consecutive =begin
commands without
the corresponding =end
. Only one =begin
may be active at
a time.
There is no specification of the formatter after the =for
command.
A command which has ended up in the middle of a paragraph or other command, such as
- =item one
- =item two <-- bad
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
""
.
An invalid POD command has been found. Valid are =head1
, =head2
,
=head3
, =head4
, =over
, =item
, =back
, =begin
, =end
,
=for
, =pod
, =cut
An invalid markup command has been encountered. Valid are:
B<>
, C<>
, E<>
, F<>
,
I<>
, L<>
, S<>
, X<>
,
Z<>
Two nested identical markup commands have been found. Generally this does not make sense.
The STRING found cannot be interpreted as a character entity.
An entity specified by number (dec, hex, oct) is out of range (1-255).
The link found cannot be parsed because it does not conform to the syntax described in perlpod.
The Z<>
sequence is supposed to be empty.
The index entry specified contains nothing but whitespace.
The commands =pod
and =cut
do not take any arguments.
A =cut
command was found without a preceding POD paragraph.
A =pod
command was found after a preceding POD paragraph.
The =back
command does not take any arguments.
These may not necessarily cause trouble, but indicate mediocre style.
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.
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.
There is a list =item
right above the flagged line that has no
text contents. You probably want to delete empty items.
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.
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.
<>
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.
A character entity was found that does not belong to the standard
ISO set or the POD specials verbar
and sol
.
The list opened with =over
does not contain any items.
=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.
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.
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.
For example if there is a =head2
in the POD file prior to a
=head1
.
There are some warnings with respect to malformed hyperlinks:
There is whitespace at the beginning or the end of the contents of L<...>.
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 ().
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>
podchecker returns the number of POD syntax errors found or -1 if there were no POD commands at all found in the file.
See SYNOPSIS
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.
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>
Pod::Checker is part of the Pod-Checker distribution, and is based on Pod::Parser.