This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
Clarify that =encoding is global in POD
[perl5.git] / pod / perlpod.pod
CommitLineData
8a93676d
SB
1
2=for comment
3This document is in Pod format. To read this, use a Pod formatter,
4like "perldoc perlpod".
5
a0d0e21e 6=head1 NAME
d74e8afc 7X<POD> X<plain old documentation>
a0d0e21e 8
8a93676d 9perlpod - the Plain Old Documentation format
a0d0e21e
LW
10
11=head1 DESCRIPTION
12
8a93676d
SB
13Pod is a simple-to-use markup language used for writing documentation
14for Perl, Perl programs, and Perl modules.
15
16Translators are available for converting Pod to various formats
17like plain text, HTML, man pages, and more.
18
19Pod markup consists of three basic kinds of paragraphs:
20L<ordinary|/"Ordinary Paragraph">,
21L<verbatim|/"Verbatim Paragraph">, and
22L<command|/"Command Paragraph">.
23
24
25=head2 Ordinary Paragraph
d74e8afc 26X<POD, ordinary paragraph>
8a93676d
SB
27
28Most paragraphs in your documentation will be ordinary blocks
29of text, like this one. You can simply type in your text without
30any markup whatsoever, and with just a blank line before and
31after. When it gets formatted, it will undergo minimal formatting,
32like being rewrapped, probably put into a proportionally spaced
33font, and maybe even justified.
34
35You can use formatting codes in ordinary paragraphs, for B<bold>,
36I<italic>, C<code-style>, L<hyperlinks|perlfaq>, and more. Such
37codes are explained in the "L<Formatting Codes|/"Formatting Codes">"
38section, below.
39
a0d0e21e 40
b74bceb9 41=head2 Verbatim Paragraph
d74e8afc 42X<POD, verbatim paragraph> X<verbatim>
a0d0e21e 43
8a93676d
SB
44Verbatim paragraphs are usually used for presenting a codeblock or
45other text which does not require any special parsing or formatting,
46and which shouldn't be wrapped.
47
48A verbatim paragraph is distinguished by having its first character
49be a space or a tab. (And commonly, all its lines begin with spaces
50and/or tabs.) It should be reproduced exactly, with tabs assumed to
51be on 8-column boundaries. There are no special formatting codes,
52so you can't italicize or anything like that. A \ means \, and
53nothing else.
54
a0d0e21e 55
b74bceb9 56=head2 Command Paragraph
d74e8afc 57X<POD, command>
b74bceb9 58
8a93676d
SB
59A command paragraph is used for special treatment of whole chunks
60of text, usually as headings or parts of lists.
61
62All command paragraphs (which are typically only one line long) start
63with "=", followed by an identifier, followed by arbitrary text that
64the command can use however it pleases. Currently recognized commands
65are
a0d0e21e 66
2757242d 67 =pod
8a93676d
SB
68 =head1 Heading Text
69 =head2 Heading Text
70 =head3 Heading Text
71 =head4 Heading Text
72 =over indentlevel
73 =item stuff
a0d0e21e 74 =back
8a93676d
SB
75 =begin format
76 =end format
77 =for format text...
2757242d
YO
78 =encoding type
79 =cut
8a93676d
SB
80
81To explain them each in detail:
82
83=over
84
85=item C<=head1 I<Heading Text>>
d74e8afc
ITB
86X<=head1> X<=head2> X<=head3> X<=head4>
87X<head1> X<head2> X<head3> X<head4>
cb1a09d0 88
8a93676d 89=item C<=head2 I<Heading Text>>
b74bceb9 90
8a93676d 91=item C<=head3 I<Heading Text>>
b74bceb9 92
8a93676d 93=item C<=head4 I<Heading Text>>
b74bceb9 94
8a93676d
SB
95Head1 through head4 produce headings, head1 being the highest
96level. The text in the rest of this paragraph is the content of the
97heading. For example:
cb1a09d0 98
8a93676d 99 =head2 Object Attributes
b74bceb9 100
8a93676d
SB
101The text "Object Attributes" comprises the heading there. (Note that
102head3 and head4 are recent additions, not supported in older Pod
103translators.) The text in these heading commands can use
104formatting codes, as seen here:
b74bceb9 105
8a93676d 106 =head2 Possible Values for C<$/>
c6b85e5d 107
8a93676d
SB
108Such commands are explained in the
109"L<Formatting Codes|/"Formatting Codes">" section, below.
c6b85e5d 110
8a93676d 111=item C<=over I<indentlevel>>
d74e8afc 112X<=over> X<=item> X<=back> X<over> X<item> X<back>
cb1a09d0 113
8a93676d 114=item C<=item I<stuff...>>
b74bceb9 115
8a93676d 116=item C<=back>
b74bceb9 117
8a93676d
SB
118Item, over, and back require a little more explanation: "=over" starts
119a region specifically for the generation of a list using "=item"
120commands, or for indenting (groups of) normal paragraphs. At the end
121of your list, use "=back" to end it. The I<indentlevel> option to
122"=over" indicates how far over to indent, generally in ems (where
123one em is the width of an "M" in the document's base font) or roughly
124comparable units; if there is no I<indentlevel> option, it defaults
125to four. (And some formatters may just ignore whatever I<indentlevel>
126you provide.) In the I<stuff> in C<=item I<stuff...>>, you may
127use formatting codes, as seen here:
b74bceb9 128
8a93676d 129 =item Using C<$|> to Control Buffering
cb1a09d0 130
8a93676d
SB
131Such commands are explained in the
132"L<Formatting Codes|/"Formatting Codes">" section, below.
b74bceb9 133
8a93676d
SB
134Note also that there are some basic rules to using "=over" ...
135"=back" regions:
b74bceb9 136
8a93676d 137=over
b74bceb9 138
8a93676d
SB
139=item *
140
141Don't use "=item"s outside of an "=over" ... "=back" region.
142
143=item *
c7c9f956 144
8a93676d
SB
145The first thing after the "=over" command should be an "=item", unless
146there aren't going to be any items at all in this "=over" ... "=back"
147region.
148
149=item *
150
151Don't put "=headI<n>" commands inside an "=over" ... "=back" region.
152
153=item *
154
155And perhaps most importantly, keep the items consistent: either use
156"=item *" for all of them, to produce bullets; or use "=item 1.",
157"=item 2.", etc., to produce numbered lists; or use "=item foo",
158"=item bar", etc. -- namely, things that look nothing like bullets or
159numbers.
160
161If you start with bullets or numbers, stick with them, as
162formatters use the first "=item" type to decide how to format the
163list.
164
165=back
166
167=item C<=cut>
d74e8afc 168X<=cut> X<cut>
8a93676d
SB
169
170To end a Pod block, use a blank line,
171then a line beginning with "=cut", and a blank
172line after it. This lets Perl (and the Pod formatter) know that
173this is where Perl code is resuming. (The blank line before the "=cut"
174is not technically necessary, but many older Pod processors require it.)
175
176=item C<=pod>
d74e8afc 177X<=pod> X<pod>
8a93676d
SB
178
179The "=pod" command by itself doesn't do much of anything, but it
180signals to Perl (and Pod formatters) that a Pod block starts here. A
181Pod block starts with I<any> command paragraph, so a "=pod" command is
182usually used just when you want to start a Pod block with an ordinary
183paragraph or a verbatim paragraph. For example:
184
185 =item stuff()
210b36aa 186
8a93676d 187 This function does stuff.
210b36aa 188
8a93676d 189 =cut
210b36aa 190
8a93676d
SB
191 sub stuff {
192 ...
193 }
210b36aa 194
8a93676d 195 =pod
210b36aa 196
8a93676d 197 Remember to check its return value, as in:
210b36aa
AMS
198
199 stuff() || die "Couldn't do stuff!";
200
8a93676d
SB
201 =cut
202
203=item C<=begin I<formatname>>
d74e8afc 204X<=begin> X<=end> X<=for> X<begin> X<end> X<for>
8a93676d
SB
205
206=item C<=end I<formatname>>
207
208=item C<=for I<formatname> I<text...>>
209
210For, begin, and end will let you have regions of text/code/data that
211are not generally interpreted as normal Pod text, but are passed
212directly to particular formatters, or are otherwise special. A
213formatter that can use that format will use the region, otherwise it
214will be completely ignored.
215
216A command "=begin I<formatname>", some paragraphs, and a
353c6505 217command "=end I<formatname>", mean that the text/data in between
8a93676d
SB
218is meant for formatters that understand the special format
219called I<formatname>. For example,
220
221 =begin html
210b36aa 222
8a93676d 223 <hr> <img src="thang.png">
c7c9f956 224 <p> This is a raw HTML paragraph </p>
210b36aa 225
8a93676d
SB
226 =end html
227
228The command "=for I<formatname> I<text...>"
229specifies that the remainder of just this paragraph (starting
230right after I<formatname>) is in that special format.
231
232 =for html <hr> <img src="thang.png">
233 <p> This is a raw HTML paragraph </p>
234
235This means the same thing as the above "=begin html" ... "=end html"
236region.
c7c9f956 237
8a93676d
SB
238That is, with "=for", you can have only one paragraph's worth
239of text (i.e., the text in "=foo targetname text..."), but with
240"=begin targetname" ... "=end targetname", you can have any amount
241of stuff inbetween. (Note that there still must be a blank line
242after the "=begin" command and a blank line before the "=end"
243command.
c7c9f956
KA
244
245Here are some examples of how to use these:
246
8a93676d
SB
247 =begin html
248
249 <br>Figure 1.<br><IMG SRC="figure1.png"><br>
250
251 =end html
252
253 =begin text
254
255 ---------------
256 | foo |
257 | bar |
258 ---------------
a6006777 259
8a93676d 260 ^^^^ Figure 1. ^^^^
a6006777 261
8a93676d 262 =end text
a6006777 263
8a93676d
SB
264Some format names that formatters currently are known to accept
265include "roff", "man", "latex", "tex", "text", and "html". (Some
266formatters will treat some of these as synonyms.)
a6006777 267
8a93676d
SB
268A format name of "comment" is common for just making notes (presumably
269to yourself) that won't appear in any formatted version of the Pod
270document:
a6006777 271
8a93676d
SB
272 =for comment
273 Make sure that all the available options are documented!
a6006777 274
8a93676d
SB
275Some I<formatnames> will require a leading colon (as in
276C<"=for :formatname">, or
277C<"=begin :formatname" ... "=end :formatname">),
278to signal that the text is not raw data, but instead I<is> Pod text
279(i.e., possibly containing formatting codes) that's just not for
280normal formatting (e.g., may not be a normal-use paragraph, but might
281be for formatting as a footnote).
c7c9f956 282
a179871b 283=item C<=encoding I<encodingname>>
d74e8afc 284X<=encoding> X<encoding>
a179871b
SB
285
286This command is used for declaring the encoding of a document. Most
287users won't need this; but if your encoding isn't US-ASCII or Latin-1,
288then put a C<=encoding I<encodingname>> command early in the document so
289that pod formatters will know how to decode the document. For
290I<encodingname>, use a name recognized by the L<Encode::Supported>
291module. Examples:
292
293 =encoding utf8
294
295 =encoding koi8-r
296
297 =encoding ShiftJIS
298
299 =encoding big5
300
8a93676d 301=back
c7c9f956 302
7a9a6fa1
DJ
303C<=encoding> affects the whole document, and must occur only once.
304
305And don't forget, when using any other command, that the command lasts up
8a93676d
SB
306until the end of its I<paragraph>, not its line. So in the
307examples below, you can see that every command needs the blank
308line after it, to end its paragraph.
cb1a09d0
AD
309
310Some examples of lists include:
311
8a93676d
SB
312 =over
313
314 =item *
315
316 First item
317
318 =item *
319
320 Second item
321
322 =back
323
324 =over
325
326 =item Foo()
327
328 Description of Foo function
329
330 =item Bar()
cb1a09d0 331
8a93676d 332 Description of Bar function
cb1a09d0 333
8a93676d 334 =back
cb1a09d0 335
cb1a09d0 336
8a93676d 337=head2 Formatting Codes
d74e8afc
ITB
338X<POD, formatting code> X<formatting code>
339X<POD, interior sequence> X<interior sequence>
cb1a09d0 340
8a93676d
SB
341In ordinary paragraphs and in some command paragraphs, various
342formatting codes (a.k.a. "interior sequences") can be used:
cb1a09d0 343
8a93676d
SB
344=for comment
345 "interior sequences" is such an opaque term.
346 Prefer "formatting codes" instead.
cb1a09d0 347
8a93676d 348=over
cb1a09d0 349
8a93676d 350=item C<IE<lt>textE<gt>> -- italic text
d74e8afc 351X<I> X<< IZ<><> >> X<POD, formatting code, italic> X<italic>
cb1a09d0 352
8a93676d
SB
353Used for emphasis ("C<be IE<lt>careful!E<gt>>") and parameters
354("C<redo IE<lt>LABELE<gt>>")
355
356=item C<BE<lt>textE<gt>> -- bold text
d74e8afc 357X<B> X<< BZ<><> >> X<POD, formatting code, bold> X<bold>
8a93676d
SB
358
359Used for switches ("C<perl's BE<lt>-nE<gt> switch>"), programs
360("C<some systems provide a BE<lt>chfnE<gt> for that>"),
361emphasis ("C<be BE<lt>careful!E<gt>>"), and so on
362("C<and that feature is known as BE<lt>autovivificationE<gt>>").
363
364=item C<CE<lt>codeE<gt>> -- code text
d74e8afc 365X<C> X<< CZ<><> >> X<POD, formatting code, code> X<code>
8a93676d
SB
366
367Renders code in a typewriter font, or gives some other indication that
368this represents program text ("C<CE<lt>gmtime($^T)E<gt>>") or some other
369form of computerese ("C<CE<lt>drwxr-xr-xE<gt>>").
370
371=item C<LE<lt>nameE<gt>> -- a hyperlink
d74e8afc 372X<L> X<< LZ<><> >> X<POD, formatting code, hyperlink> X<hyperlink>
8a93676d
SB
373
374There are various syntaxes, listed below. In the syntaxes given,
375C<text>, C<name>, and C<section> cannot contain the characters
376'/' and '|'; and any '<' or '>' should be matched.
377
378=over
379
380=item *
cb1a09d0 381
8a93676d 382C<LE<lt>nameE<gt>>
cb1a09d0 383
8a93676d
SB
384Link to a Perl manual page (e.g., C<LE<lt>Net::PingE<gt>>). Note
385that C<name> should not contain spaces. This syntax
386is also occasionally used for references to UNIX man pages, as in
387C<LE<lt>crontab(5)E<gt>>.
388
389=item *
390
391C<LE<lt>name/"sec"E<gt>> or C<LE<lt>name/secE<gt>>
392
393Link to a section in other manual page. E.g.,
394C<LE<lt>perlsyn/"For Loops"E<gt>>
395
396=item *
397
398C<LE<lt>/"sec"E<gt>> or C<LE<lt>/secE<gt>> or C<LE<lt>"sec"E<gt>>
399
400Link to a section in this manual page. E.g.,
401C<LE<lt>/"Object Methods"E<gt>>
a0d0e21e 402
b74bceb9
AB
403=back
404
8a93676d
SB
405A section is started by the named heading or item. For
406example, C<LE<lt>perlvar/$.E<gt>> or C<LE<lt>perlvar/"$."E<gt>> both
407link to the section started by "C<=item $.>" in perlvar. And
408C<LE<lt>perlsyn/For LoopsE<gt>> or C<LE<lt>perlsyn/"For Loops"E<gt>>
409both link to the section started by "C<=head2 For Loops>"
410in perlsyn.
411
412To control what text is used for display, you
413use "C<LE<lt>text|...E<gt>>", as in:
414
415=over
416
417=item *
418
419C<LE<lt>text|nameE<gt>>
420
421Link this text to that manual page. E.g.,
422C<LE<lt>Perl Error Messages|perldiagE<gt>>
423
424=item *
425
426C<LE<lt>text|name/"sec"E<gt>> or C<LE<lt>text|name/secE<gt>>
427
428Link this text to that section in that manual page. E.g.,
8325efec 429C<LE<lt>postfix "if"|perlsyn/"Statement Modifiers"E<gt>>
8a93676d
SB
430
431=item *
432
433C<LE<lt>text|/"sec"E<gt>> or C<LE<lt>text|/secE<gt>>
434or C<LE<lt>text|"sec"E<gt>>
435
436Link this text to that section in this manual page. E.g.,
437C<LE<lt>the various attributes|/"Member Data"E<gt>>
438
439=back
440
441Or you can link to a web page:
442
443=over
444
445=item *
446
447C<LE<lt>scheme:...E<gt>>
448
449Links to an absolute URL. For example,
450C<LE<lt>http://www.perl.org/E<gt>>. But note
451that there is no corresponding C<LE<lt>text|scheme:...E<gt>> syntax, for
452various reasons.
453
454=back
455
456=item C<EE<lt>escapeE<gt>> -- a character escape
d74e8afc 457X<E> X<< EZ<><> >> X<POD, formatting code, escape> X<escape>
8a93676d
SB
458
459Very similar to HTML/XML C<&I<foo>;> "entity references":
460
461=over
462
463=item *
464
465C<EE<lt>ltE<gt>> -- a literal E<lt> (less than)
466
467=item *
468
469C<EE<lt>gtE<gt>> -- a literal E<gt> (greater than)
470
471=item *
472
473C<EE<lt>verbarE<gt>> -- a literal | (I<ver>tical I<bar>)
474
475=item *
476
477C<EE<lt>solE<gt>> = a literal / (I<sol>idus)
478
479The above four are optional except in other formatting codes,
480notably C<LE<lt>...E<gt>>, and when preceded by a
481capital letter.
482
483=item *
484
485C<EE<lt>htmlnameE<gt>>
486
487Some non-numeric HTML entity name, such as C<EE<lt>eacuteE<gt>>,
488meaning the same thing as C<&eacute;> in HTML -- i.e., a lowercase
489e with an acute (/-shaped) accent.
490
491=item *
492
493C<EE<lt>numberE<gt>>
494
495The ASCII/Latin-1/Unicode character with that number. A
496leading "0x" means that I<number> is hex, as in
497C<EE<lt>0x201EE<gt>>. A leading "0" means that I<number> is octal,
498as in C<EE<lt>075E<gt>>. Otherwise I<number> is interpreted as being
499in decimal, as in C<EE<lt>181E<gt>>.
500
501Note that older Pod formatters might not recognize octal or
502hex numeric escapes, and that many formatters cannot reliably
503render characters above 255. (Some formatters may even have
504to use compromised renderings of Latin-1 characters, like
505rendering C<EE<lt>eacuteE<gt>> as just a plain "e".)
506
507=back
508
509=item C<FE<lt>filenameE<gt>> -- used for filenames
d74e8afc 510X<F> X<< FZ<><> >> X<POD, formatting code, filename> X<filename>
8a93676d
SB
511
512Typically displayed in italics. Example: "C<FE<lt>.cshrcE<gt>>"
513
514=item C<SE<lt>textE<gt>> -- text contains non-breaking spaces
d74e8afc
ITB
515X<S> X<< SZ<><> >> X<POD, formatting code, non-breaking space>
516X<non-breaking space>
8a93676d
SB
517
518This means that the words in I<text> should not be broken
519across lines. Example: S<C<SE<lt>$x ? $y : $zE<gt>>>.
520
521=item C<XE<lt>topic nameE<gt>> -- an index entry
d74e8afc 522X<X> X<< XZ<><> >> X<POD, formatting code, index entry> X<index entry>
8a93676d
SB
523
524This is ignored by most formatters, but some may use it for building
525indexes. It always renders as empty-string.
526Example: C<XE<lt>absolutizing relative URLsE<gt>>
527
528=item C<ZE<lt>E<gt>> -- a null (zero-effect) formatting code
d74e8afc 529X<Z> X<< ZZ<><> >> X<POD, formatting code, null> X<null>
8a93676d
SB
530
531This is rarely used. It's one way to get around using an
532EE<lt>...E<gt> code sometimes. For example, instead of
533"C<NEE<lt>ltE<gt>3>" (for "NE<lt>3") you could write
534"C<NZE<lt>E<gt>E<lt>3>" (the "ZE<lt>E<gt>" breaks up the "N" and
535the "E<lt>" so they can't be considered
536the part of a (fictitious) "NE<lt>...E<gt>" code.
537
538=for comment
539 This was formerly explained as a "zero-width character". But it in
540 most parser models, it parses to nothing at all, as opposed to parsing
541 as if it were a E<zwnj> or E<zwj>, which are REAL zero-width characters.
542 So "width" and "character" are exactly the wrong words.
543
544=back
545
546Most of the time, you will need only a single set of angle brackets to
547delimit the beginning and end of formatting codes. However,
548sometimes you will want to put a real right angle bracket (a
549greater-than sign, '>') inside of a formatting code. This is particularly
550common when using a formatting code to provide a different font-type for a
551snippet of code. As with all things in Perl, there is more than
552one way to do it. One way is to simply escape the closing bracket
553using an C<E> code:
5455df32
GS
554
555 C<$a E<lt>=E<gt> $b>
556
557This will produce: "C<$a E<lt>=E<gt> $b>"
558
8a93676d
SB
559A more readable, and perhaps more "plain" way is to use an alternate
560set of delimiters that doesn't require a single ">" to be escaped. With
561the Pod formatters that are standard starting with perl5.5.660, doubled
562angle brackets ("<<" and ">>") may be used I<if and only if there is
563whitespace right after the opening delimiter and whitespace right
564before the closing delimiter!> For example, the following will
565do the trick:
d74e8afc 566X<POD, formatting code, escaping with multiple brackets>
5455df32
GS
567
568 C<< $a <=> $b >>
569
570In fact, you can use as many repeated angle-brackets as you like so
571long as you have the same number of them in the opening and closing
572delimiters, and make sure that whitespace immediately follows the last
8a93676d
SB
573'<' of the opening delimiter, and immediately precedes the first '>'
574of the closing delimiter. (The whitespace is ignored.) So the
575following will also work:
d74e8afc 576X<POD, formatting code, escaping with multiple brackets>
5455df32
GS
577
578 C<<< $a <=> $b >>>
8a93676d 579 C<<<< $a <=> $b >>>>
5455df32 580
8a93676d
SB
581And they all mean exactly the same as this:
582
583 C<$a E<lt>=E<gt> $b>
584
585As a further example, this means that if you wanted to put these bits of
586code in C<C> (code) style:
587
588 open(X, ">>thing.dat") || die $!
589 $foo->bar();
590
591you could do it like so:
592
593 C<<< open(X, ">>thing.dat") || die $! >>>
594 C<< $foo->bar(); >>
5455df32 595
8a93676d
SB
596which is presumably easier to read than the old way:
597
598 C<open(X, "E<gt>E<gt>thing.dat") || die $!>
c58e3c1c 599 C<$foo-E<gt>bar();>
8a93676d
SB
600
601This is currently supported by pod2text (Pod::Text), pod2man (Pod::Man),
602and any other pod2xxx or Pod::Xxxx translators that use
603Pod::Parser 1.093 or later, or Pod::Tree 1.02 or later.
5455df32 604
b74bceb9 605=head2 The Intent
d74e8afc 606X<POD, intent of>
3141265f 607
8a93676d
SB
608The intent is simplicity of use, not power of expression. Paragraphs
609look like paragraphs (block format), so that they stand out
610visually, and so that I could run them through C<fmt> easily to reformat
611them (that's F7 in my version of B<vi>, or Esc Q in my version of
612B<emacs>). I wanted the translator to always leave the C<'> and C<`> and
613C<"> quotes alone, in verbatim mode, so I could slurp in a
614working program, shift it over four spaces, and have it print out, er,
615verbatim. And presumably in a monospace font.
616
617The Pod format is not necessarily sufficient for writing a book. Pod
618is just meant to be an idiot-proof common source for nroff, HTML,
619TeX, and other markup languages, as used for online
620documentation. Translators exist for B<pod2text>, B<pod2html>,
621B<pod2man> (that's for nroff(1) and troff(1)), B<pod2latex>, and
622B<pod2fm>. Various others are available in CPAN.
623
a0d0e21e 624
b74bceb9 625=head2 Embedding Pods in Perl Modules
d74e8afc 626X<POD, embedding>
4633a7c4 627
8a93676d
SB
628You can embed Pod documentation in your Perl modules and scripts.
629Start your documentation with an empty line, a "=head1" command at the
630beginning, and end it with a "=cut" command and an empty line. Perl
631will ignore the Pod text. See any of the supplied library modules for
632examples. If you're going to put your Pod at the end of the file, and
633you're using an __END__ or __DATA__ cut mark, make sure to put an
634empty line there before the first Pod command.
cb1a09d0 635
8a93676d 636 __END__
cb1a09d0 637
8a93676d 638 =head1 NAME
cb1a09d0 639
8a93676d 640 Time::Local - efficiently compute time from local and GMT time
cb1a09d0 641
8a93676d
SB
642Without that empty line before the "=head1", many translators wouldn't
643have recognized the "=head1" as starting a Pod block.
cb1a09d0 644
8a93676d 645=head2 Hints for Writing Pod
1294c5d8 646
8a93676d 647=over
1294c5d8
JM
648
649=item *
d74e8afc 650X<podchecker> X<POD, validating>
1294c5d8 651
8a93676d
SB
652The B<podchecker> command is provided for checking Pod syntax for errors
653and warnings. For example, it checks for completely blank lines in
654Pod blocks and for unknown commands and formatting codes. You should
655still also pass your document through one or more translators and proofread
656the result, or print out the result and proofread that. Some of the
657problems found may be bugs in the translators, which you may or may not
658wish to work around.
1294c5d8
JM
659
660=item *
661
8a93676d 662If you're more familiar with writing in HTML than with writing in Pod, you
210b36aa 663can try your hand at writing documentation in simple HTML, and converting
8a93676d
SB
664it to Pod with the experimental L<Pod::HTML2Pod|Pod::HTML2Pod> module,
665(available in CPAN), and looking at the resulting code. The experimental
666L<Pod::PXML|Pod::PXML> module in CPAN might also be useful.
667
668=item *
669
670Many older Pod translators require the lines before every Pod
671command and after every Pod command (including "=cut"!) to be a blank
672line. Having something like this:
673
674 # - - - - - - - - - - - -
675 =item $firecracker->boom()
210b36aa 676
8a93676d
SB
677 This noisily detonates the firecracker object.
678 =cut
679 sub boom {
680 ...
681
682...will make such Pod translators completely fail to see the Pod block
683at all.
684
685Instead, have it like this:
686
687 # - - - - - - - - - - - -
210b36aa 688
8a93676d 689 =item $firecracker->boom()
210b36aa 690
8a93676d 691 This noisily detonates the firecracker object.
210b36aa 692
8a93676d 693 =cut
210b36aa 694
8a93676d
SB
695 sub boom {
696 ...
697
698=item *
699
700Some older Pod translators require paragraphs (including command
701paragraphs like "=head2 Functions") to be separated by I<completely>
702empty lines. If you have an apparently empty line with some spaces
703on it, this might not count as a separator for those translators, and
704that could cause odd formatting.
705
706=item *
1294c5d8 707
8a93676d
SB
708Older translators might add wording around an LE<lt>E<gt> link, so that
709C<LE<lt>Foo::BarE<gt>> may become "the Foo::Bar manpage", for example.
710So you shouldn't write things like C<the LE<lt>fooE<gt>
711documentation>, if you want the translated document to read sensibly
712-- instead write C<the LE<lt>Foo::Bar|Foo::BarE<gt> documentation> or
713C<LE<lt>the Foo::Bar documentation|Foo::BarE<gt>>, to control how the
714link comes out.
b74bceb9 715
1294c5d8
JM
716=item *
717
8a93676d
SB
718Going past the 70th column in a verbatim block might be ungracefully
719wrapped by some formatters.
1294c5d8
JM
720
721=back
722
cb1a09d0
AD
723=head1 SEE ALSO
724
8a93676d
SB
725L<perlpodspec>, L<perlsyn/"PODs: Embedded Documentation">,
726L<perlnewmod>, L<perldoc>, L<pod2html>, L<pod2man>, L<podchecker>.
4633a7c4 727
cb1a09d0 728=head1 AUTHOR
a0d0e21e 729
8a93676d 730Larry Wall, Sean M. Burke
a0d0e21e 731
8a93676d 732=cut