Pod::Checker(3p)Perl Programmers Reference Guide Pod::Checker(3p)
Pod::Checker, podchecker() - check pod documents for syntax
errors
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 "Warn-
ings".
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<...>".
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+ 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 inter-
nal links but should be links to something else.
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"
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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 con-
form 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 whi-
tespace.
* 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 medio-
cre 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
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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 ver-
batim 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 contin-
ued 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 -warn-
ings 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 defini-
tion 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 immedi-
ately 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".
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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 delimiter in
case of doubt, one ought to escape these literal charac-
ters 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 actu-
ally starting to convert. This is expensive in terms of exe-
cution 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 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
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required methods later. The following options are recog-
nized:
"-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
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collapsed to a single blank.
"$checker->idx()"
Add (if argument specified) and retrieve the index
entries (as defined by "X<>") of the current POD. They
consist of plain text, each piece of whitespace is col-
lapsed to a single blank.
"$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>
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