1Pod::Checker(3pm) Perl Programmers Reference Guide Pod::Checker(3pm)
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6 Pod::Checker, podchecker() - check pod documents for syntax errors
7
9 use Pod::Checker;
10 $syntax_okay = podchecker($filepath, $outputpath, %options);
12 my $checker = new Pod::Checker %options;
14 $checker->parse_from_file($filepath, \*STDERR);
15
17 $filepath is the input POD to read and $outputpath is where to write
18 POD syntax error messages. Either argument may be a scalar indicating a
19 file-path, or else a reference to an open filehandle. If unspecified,
20 the input-file it defaults to "\*STDIN", and the output-file defaults
21 to "\*STDERR".
22 podchecker()
24 This function can take a hash of options:
25 -warnings => val
27 Turn warnings on/off. val is usually 1 for on, but higher values
28 trigger additional warnings. See "Warnings".
29
31 podchecker will perform syntax checking of Perl5 POD format
32 documentation.
33 Curious/ambitious users are welcome to propose additional features they
35 wish to see in Pod::Checker and podchecker and verify that the checks
36 are consistent with perlpod.
37 The following checks are currently performed:
39 · Unknown '=xxxx' commands, unknown 'X<...>' interior-sequences, and
41 unterminated interior sequences.
42 · Check for proper balancing of "=begin" and "=end". The contents of
44 such a block are generally ignored, i.e. no syntax checks are
45 performed.
46 · Check for proper nesting and balancing of "=over", "=item" and
48 "=back".
49 · Check for same nested interior-sequences (e.g. "L<...L<...>...>").
51 · Check for malformed or non-existing entities "E<...>".
53 · Check for correct syntax of hyperlinks "L<...>". See perlpod for
55 details.
56 · Check for unresolved document-internal links. This check may also
58 reveal misspelled links that seem to be internal links but should
59 be links to something else.
60
62 Errors
63 · empty =headn
64 A heading ("=head1" or "=head2") without any text? That ain't no
66 heading!
67 · =over on line N without closing =back
69 The "=over" command does not have a corresponding "=back" before
71 the next heading ("=head1" or "=head2") or the end of the file.
72 · =item without previous =over
74 · =back without previous =over
76 An "=item" or "=back" command has been found outside a
78 "=over"/"=back" block.
79 · No argument for =begin
81 A "=begin" command was found that is not followed by the formatter
83 specification.
84 · =end without =begin
86 A standalone "=end" command was found.
88 · Nested =begin's
90 There were at least two consecutive "=begin" commands without the
92 corresponding "=end". Only one "=begin" may be active at a time.
93 · =for without formatter specification
95 There is no specification of the formatter after the "=for"
97 command.
98 · unresolved internal link NAME
100 The given link to NAME does not have a matching node in the current
102 POD. This also happened when a single word node name is not
103 enclosed in "".
104 · Unknown command "CMD"
106 An invalid POD command has been found. Valid are "=head1",
108 "=head2", "=head3", "=head4", "=over", "=item", "=back", "=begin",
109 "=end", "=for", "=pod", "=cut"
110 · Unknown interior-sequence "SEQ"
112 An invalid markup command has been encountered. Valid are: "B<>",
114 "C<>", "E<>", "F<>", "I<>", "L<>", "S<>", "X<>", "Z<>"
115 · nested commands CMD<...CMD<...>...>
117 Two nested identical markup commands have been found. Generally
119 this does not make sense.
120 · garbled entity STRING
122 The STRING found cannot be interpreted as a character entity.
124 · Entity number out of range
126 An entity specified by number (dec, hex, oct) is out of range
128 (1-255).
129 · malformed link L<>
131 The link found cannot be parsed because it does not conform to the
133 syntax described in perlpod.
134 · nonempty Z<>
136 The "Z<>" sequence is supposed to be empty.
138 · empty X<>
140 The index entry specified contains nothing but whitespace.
142 · Spurious text after =pod / =cut
144 The commands "=pod" and "=cut" do not take any arguments.
146 · Spurious character(s) after =back
148 The "=back" command does not take any arguments.
150 Warnings
152 These may not necessarily cause trouble, but indicate mediocre style.
153 · multiple occurrence of link target name
155 The POD file has some "=item" and/or "=head" commands that have the
157 same text. Potential hyperlinks to such a text cannot be unique
158 then. This warning is printed only with warning level greater than
159 one.
160 · line containing nothing but whitespace in paragraph
162 There is some whitespace on a seemingly empty line. POD is very
164 sensitive to such things, so this is flagged. vi users switch on
165 the list option to avoid this problem.
166 · previous =item has no contents
168 There is a list "=item" right above the flagged line that has no
170 text contents. You probably want to delete empty items.
171 · preceding non-item paragraph(s)
173 A list introduced by "=over" starts with a text or verbatim
175 paragraph, but continues with "=item"s. Move the non-item paragraph
176 out of the "=over"/"=back" block.
177 · =item type mismatch (one vs. two)
179 A list started with e.g. a bullet-like "=item" and continued with a
181 numbered one. This is obviously inconsistent. For most translators
182 the type of the first "=item" determines the type of the list.
183 · N unescaped "<>" in paragraph
185 Angle brackets not written as "<lt>" and "<gt>" can potentially
187 cause errors as they could be misinterpreted as markup commands.
188 This is only printed when the -warnings level is greater than 1.
189 · Unknown entity
191 A character entity was found that does not belong to the standard
193 ISO set or the POD specials "verbar" and "sol".
194 · No items in =over
196 The list opened with "=over" does not contain any items.
198 · No argument for =item
200 "=item" without any parameters is deprecated. It should either be
202 followed by "*" to indicate an unordered list, by a number
203 (optionally followed by a dot) to indicate an ordered (numbered)
204 list or simple text for a definition list.
205 · empty section in previous paragraph
207 The previous section (introduced by a "=head" command) does not
209 contain any text. This usually indicates that something is missing.
210 Note: A "=head1" followed immediately by "=head2" does not trigger
211 this warning.
212 · Verbatim paragraph in NAME section
214 The NAME section ("=head1 NAME") should consist of a single
216 paragraph with the script/module name, followed by a dash `-' and a
217 very short description of what the thing is good for.
218 · =headn without preceding higher level
220 For example if there is a "=head2" in the POD file prior to a
222 "=head1".
223 Hyperlinks
225 There are some warnings with respect to malformed hyperlinks:
226 · ignoring leading/trailing whitespace in link
228 There is whitespace at the beginning or the end of the contents of
230 L<...>.
231 · (section) in '$page' deprecated
233 There is a section detected in the page name of L<...>, e.g.
235 "L<passwd(2)>". POD hyperlinks may point to POD documents only.
236 Please write "C<passwd(2)>" instead. Some formatters are able to
237 expand this to appropriate code. For links to (builtin) functions,
238 please say "L<perlfunc/mkdir>", without ().
239 · alternative text/node '%s' contains non-escaped | or /
241 The characters "|" and "/" are special in the L<...> context.
243 Although the hyperlink parser does its best to determine which "/"
244 is text and which is a delimiter in case of doubt, one ought to
245 escape these literal characters like this:
246 / E<sol>
248 | E<verbar>
249
251 podchecker returns the number of POD syntax errors found or -1 if there
252 were no POD commands at all found in the file.
253
255 See "SYNOPSIS"
256
258 While checking, this module collects document properties, e.g. the
259 nodes for hyperlinks ("=headX", "=item") and index entries ("X<>").
260 POD translators can use this feature to syntax-check and get the nodes
261 in a first pass before actually starting to convert. This is expensive
262 in terms of execution time, but allows for very robust conversions.
263 Since PodParser-1.24 the Pod::Checker module uses only the poderror
265 method to print errors and warnings. The summary output (e.g. "Pod
266 syntax OK") has been dropped from the module and has been included in
267 podchecker (the script). This allows users of Pod::Checker to control
268 completely the output behavior. Users of podchecker (the script) get
269 the well-known behavior.
270 "Pod::Checker->new( %options )"
272 Return a reference to a new Pod::Checker object that inherits from
273 Pod::Parser and is used for calling the required methods later. The
274 following options are recognized:
275 "-warnings => num"
277 Print warnings if "num" is true. The higher the value of "num",
278 the more warnings are printed. Currently there are only levels 1
279 and 2.
280 "-quiet => num"
282 If "num" is true, do not print any errors/warnings. This is
283 useful when Pod::Checker is used to munge POD code into plain text
284 from within POD formatters.
285 "$checker->poderror( @args )"
287 "$checker->poderror( {%opts}, @args )"
288 Internal method for printing errors and warnings. If no options are
289 given, simply prints "@_". The following options are recognized and
290 used to form the output:
291 -msg
293 A message to print prior to @args.
295 -line
297 The line number the error occurred in.
299 -file
301 The file (name) the error occurred in.
303 -severity
305 The error level, should be 'WARNING' or 'ERROR'.
307 "$checker->num_errors()"
309 Set (if argument specified) and retrieve the number of errors
310 found.
311 "$checker->num_warnings()"
313 Set (if argument specified) and retrieve the number of warnings
314 found.
315 "$checker->name()"
317 Set (if argument specified) and retrieve the canonical name of POD
318 as found in the "=head1 NAME" section.
319 "$checker->node()"
321 Add (if argument specified) and retrieve the nodes (as defined by
322 "=headX" and "=item") of the current POD. The nodes are returned in
323 the order of their occurrence. They consist of plain text, each
324 piece of whitespace is collapsed to a single blank.
325 "$checker->idx()"
327 Add (if argument specified) and retrieve the index entries (as
328 defined by "X<>") of the current POD. They consist of plain text,
329 each piece of whitespace is collapsed to a single blank.
330 "$checker->hyperlink()"
332 Add (if argument specified) and retrieve the hyperlinks (as defined
333 by "L<>") of the current POD. They consist of a 2-item array: line
334 number and "Pod::Hyperlink" object.
335
337 Please report bugs using <http://rt.cpan.org>.
338 Brad Appleton <bradapp@enteract.com> (initial version), Marek Rouchal
340 <marekr@cpan.org>
341 Based on code for Pod::Text::pod2text() written by Tom Christiansen
343 <tchrist@mox.perl.com>
344perl v5.12.4 2011-06-01 Pod::Checker(3pm)