Pod::Checker(3) User Contributed Perl Documentation Pod::Checker(3)
NAME
Pod::Checker - check pod documents for syntax errors
SYNOPSIS
use Pod::Checker;
$syntax_okay = podchecker($filepath, $outputpath, %options);
my $checker = Pod::Checker->new(%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".
-quiet => val
If "val" is true, do not print any errors/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 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
o You forgot a '=back' before '=headN'
o =over is the last thing in the document?!
The "=over" command does not have a corresponding "=back" before
the next heading ("=head1" or "=head2") or the end of the file.
o '=item' outside of any '=over'
o =back without =over
An "=item" or "=back" command has been found outside a
"=over"/"=back" block.
o Can't have a 0 in =over N
You need to indent a strictly positive number of spaces, not 0.
o =over should be: '=over' or '=over positive_number'
Either have an argumentless =over, or have its argument a strictly
positive number.
o =begin TARGET without matching =end TARGET
A "=begin" command was found that has no matching =end command.
o =begin without a target?
A "=begin" command was found that is not followed by the formatter
specification.
o =end TARGET without matching =begin.
A standalone "=end" command was found.
o '=end' without a target?
'=end' directives need to have a target, just like =begin
directives.
o '=end TARGET' is invalid.
TARGET needs to be one word
o =end CONTENT doesn't match =begin TARGET
CONTENT needs to match =begin's TARGET.
o =for without a target?
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 directive: CMD
An invalid POD command has been found. Valid are "=head1",
"=head2", "=head3", "=head4", "=over", "=item", "=back", "=begin",
"=end", "=for", "=pod", "=cut"
o Deleting unknown formatting code SEQ
An invalid markup command has been encountered. Valid are: "B<>",
"C<>", "E<>", "F<>", "I<>", "L<>", "S<>", "X<>", "Z<>"
o Unterminated SEQ<> sequence
An unclosed formatting code
o An E<...> surrounding strange content
The STRING found cannot be interpreted as a character entity.
o An empty E<>
o An empty "L<>"
o An empty X<>
There needs to be content inside E, L, and X formatting codes.
o A non-empty Z<>
The "Z<>" sequence is supposed to be empty.
o Spurious text after =pod / =cut
The commands "=pod" and "=cut" do not take any arguments.
o =back doesn't take any parameters, but you said =back ARGUMENT
The "=back" command does not take any arguments.
o =pod directives shouldn't be over one line long! Ignoring all N
lines of content
Self explanatory
o =cut found outside a pod block.
A '=cut' directive found in the middle of non-POD
o Invalid =encoding syntax: CONTENT
Syntax error in =encoding directive
Warnings
These may not necessarily cause trouble, but indicate mediocre style.
o nested commands CMD<...CMD<...>...>
Two nested identical markup commands have been found. Generally
this does not make sense.
o multiple occurrences (N) 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.
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 =item has no contents
There is a list "=item" that has no text contents. You probably
want to delete empty items.
o You can't have =items (as at line N) unless the first thing after
the =over is an =item
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 Expected '=item EXPECTED VALUE'
o Expected '=item *'
o Possible =item type mismatch: 'x' found leading a supposed
definition =item
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 You have '=item x' instead of the expected '=item N'
Erroneous numbering of =item numbers; they need to ascend
consecutively.
o Unknown E content in E<CONTENT>
A character entity was found that does not belong to the standard
ISO set or the POD specials "verbar" and "sol". Currently, this
warning only appears if a character entity was found that does not
have a Unicode character. This should be fixed to adhere to the
original warning.
o empty =over/=back block
The list opened with "=over" does not contain anything.
o empty section in previous paragraph
The previous section (introduced by a "=head" command) does not
contain any valid content. 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 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>
Note that the line number of the error/warning may refer to the line
number of the start of the paragraph in which the error/warning exists,
not the line number that the error/warning is on. This bug is present
in errors/warnings related to formatting codes. This should be fixed.
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"
SCRIPTS
The podchecker script that comes with this distribution is a lean
wrapper around this module. See the online manual with
podchecker -help
podchecker -man
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 v1.24 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.
v1.45 inherits from Pod::Simple as opposed to all previous versions
inheriting from Pod::Parser. Do not use Pod::Simple's interface when
using Pod::Checker unless it is documented somewhere on this page. I
repeat, DO NOT USE POD::SIMPLE'S INTERFACE.
"Pod::Checker->new( %options )"
Return a reference to a new Pod::Checker object that inherits from
Pod::Simple 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 )"
"$checker->poderror( {%opts}, @args )"
Internal method for printing errors and warnings. If no options are
given, simply prints "@_". The following options are recognized and
used to form the output:
-msg
A message to print prior to @args.
-line
The line number the error occurred in.
-file
The file (name) the error occurred in. Defaults to the name of the
current file being processed.
-severity
The error level, should be 'WARNING' or 'ERROR'.
"$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->hyperlinks()"
Retrieve an array containing the hyperlinks to things outside the
current POD (as defined by "L<>").
Each is an instance of a class with the following methods:
line()
Returns the approximate line number in which the link was
encountered
type()
Returns the type of the link; one of: "url" for things like
"http://www.foo", "man" for man pages, or "pod".
page()
Returns the linked-to page or url.
node()
Returns the anchor or node within the linked-to page, or an empty
string ("") if none appears in the link.
AUTHOR
Please report bugs using <http://rt.cpan.org>;.
Brad Appleton <bradapp AT enteract.com> (initial version), Marek Rouchal
<marekr AT cpan.org>, Marc Green <marcgreen AT cpan.org> (port to
Pod::Simple) Ricardo Signes <rjbs AT cpan.org> (more porting to
Pod::Simple) Karl Williamson <khw AT cpan.org> (more porting to
Pod::Simple)
Based on code for Pod::Text::pod2text() written by Tom Christiansen
<tchrist AT mox.com>
perl v5.26.3 2016-05-30 Pod::Checker(3)
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