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Update Pod-Usage to CPAN version 1.63
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1#############################################################################
2# Pod/Usage.pm -- print usage messages for the running script.
3#
4# Copyright (C) 1996-2000 by Bradford Appleton. All rights reserved.
5# This file is part of "PodParser". PodParser is free software;
6# you can redistribute it and/or modify it under the same terms
7# as Perl itself.
8#############################################################################
9
10package Pod::Usage;
11use strict;
12
13use vars qw($VERSION @ISA @EXPORT);
2ed39982 14$VERSION = '1.63'; ## Current version of this package
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15require 5.006; ## requires this Perl version or later
16
17#use diagnostics;
18use Carp;
19use Config;
20use Exporter;
21use File::Spec;
22
23@EXPORT = qw(&pod2usage);
24BEGIN {
25 $Pod::Usage::Formatter ||= 'Pod::Text';
26 eval "require $Pod::Usage::Formatter";
27 die $@ if $@;
28 @ISA = ( $Pod::Usage::Formatter );
29}
30
31our $MAX_HEADING_LEVEL = 3;
32
33##---------------------------------------------------------------------------
34
35##---------------------------------
36## Function definitions begin here
37##---------------------------------
38
39sub pod2usage {
40 local($_) = shift;
41 my %opts;
42 ## Collect arguments
43 if (@_ > 0) {
44 ## Too many arguments - assume that this is a hash and
45 ## the user forgot to pass a reference to it.
46 %opts = ($_, @_);
47 }
48 elsif (!defined $_) {
49 $_ = '';
50 }
51 elsif (ref $_) {
52 ## User passed a ref to a hash
53 %opts = %{$_} if (ref($_) eq 'HASH');
54 }
55 elsif (/^[-+]?\d+$/) {
56 ## User passed in the exit value to use
57 $opts{'-exitval'} = $_;
58 }
59 else {
60 ## User passed in a message to print before issuing usage.
61 $_ and $opts{'-message'} = $_;
62 }
63
64 ## Need this for backward compatibility since we formerly used
65 ## options that were all uppercase words rather than ones that
66 ## looked like Unix command-line options.
67 ## to be uppercase keywords)
68 %opts = map {
69 my ($key, $val) = ($_, $opts{$_});
70 $key =~ s/^(?=\w)/-/;
71 $key =~ /^-msg/i and $key = '-message';
72 $key =~ /^-exit/i and $key = '-exitval';
73 lc($key) => $val;
74 } (keys %opts);
75
76 ## Now determine default -exitval and -verbose values to use
77 if ((! defined $opts{'-exitval'}) && (! defined $opts{'-verbose'})) {
78 $opts{'-exitval'} = 2;
79 $opts{'-verbose'} = 0;
80 }
81 elsif (! defined $opts{'-exitval'}) {
82 $opts{'-exitval'} = ($opts{'-verbose'} > 0) ? 1 : 2;
83 }
84 elsif (! defined $opts{'-verbose'}) {
85 $opts{'-verbose'} = (lc($opts{'-exitval'}) eq 'noexit' ||
86 $opts{'-exitval'} < 2);
87 }
88
89 ## Default the output file
90 $opts{'-output'} = (lc($opts{'-exitval'}) eq 'noexit' ||
91 $opts{'-exitval'} < 2) ? \*STDOUT : \*STDERR
92 unless (defined $opts{'-output'});
93 ## Default the input file
94 $opts{'-input'} = $0 unless (defined $opts{'-input'});
95
2ed39982 96 ## Look up input file in path if it doesn't exist.
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97 unless ((ref $opts{'-input'}) || (-e $opts{'-input'})) {
98 my $basename = $opts{'-input'};
99 my $pathsep = ($^O =~ /^(?:dos|os2|MSWin32)$/i) ? ';'
100 : (($^O eq 'MacOS' || $^O eq 'VMS') ? ',' : ':');
101 my $pathspec = $opts{'-pathlist'} || $ENV{PATH} || $ENV{PERL5LIB};
102
103 my @paths = (ref $pathspec) ? @$pathspec : split($pathsep, $pathspec);
104 for my $dirname (@paths) {
105 $_ = File::Spec->catfile($dirname, $basename) if length;
106 last if (-e $_) && ($opts{'-input'} = $_);
107 }
108 }
109
110 ## Now create a pod reader and constrain it to the desired sections.
111 my $parser = new Pod::Usage(USAGE_OPTIONS => \%opts);
112 if ($opts{'-verbose'} == 0) {
113 $parser->select('(?:SYNOPSIS|USAGE)\s*');
114 }
115 elsif ($opts{'-verbose'} == 1) {
116 my $opt_re = '(?i)' .
117 '(?:OPTIONS|ARGUMENTS)' .
118 '(?:\s*(?:AND|\/)\s*(?:OPTIONS|ARGUMENTS))?';
119 $parser->select( '(?:SYNOPSIS|USAGE)\s*', $opt_re, "DESCRIPTION/$opt_re" );
120 }
121 elsif ($opts{'-verbose'} >= 2 && $opts{'-verbose'} != 99) {
122 $parser->select('.*');
123 }
124 elsif ($opts{'-verbose'} == 99) {
125 my $sections = $opts{'-sections'};
126 $parser->select( (ref $sections) ? @$sections : $sections );
127 $opts{'-verbose'} = 1;
128 }
129
130 ## Check for perldoc
131 my $progpath = File::Spec->catfile($Config{scriptdirexp}
132 || $Config{scriptdir}, 'perldoc');
133
134 my $version = sprintf("%vd",$^V);
135 if ($Config{versiononly} and $Config{startperl} =~ /\Q$version\E$/ ) {
136 $progpath .= $version;
137 }
138 $opts{'-noperldoc'} = 1 unless -e $progpath;
139
140 ## Now translate the pod document and then exit with the desired status
141 if ( !$opts{'-noperldoc'}
142 and $opts{'-verbose'} >= 2
143 and !ref($opts{'-input'})
144 and $opts{'-output'} == \*STDOUT )
145 {
146 ## spit out the entire PODs. Might as well invoke perldoc
147 print { $opts{'-output'} } ($opts{'-message'}, "\n") if($opts{'-message'});
148 if(defined $opts{-input} && $opts{-input} =~ /^\s*(\S.*?)\s*$/) {
149 # the perldocs back to 5.005 should all have -F
150 # without -F there are warnings in -T scripts
151 system($progpath, '-F', $1);
152 if($?) {
153 # RT16091: fall back to more if perldoc failed
154 system(($Config{pager} || $ENV{PAGER} || '/bin/more'), $1);
155 }
156 } else {
157 croak "Unspecified input file or insecure argument.\n";
158 }
159 }
160 else {
161 $parser->parse_from_file($opts{'-input'}, $opts{'-output'});
162 }
163
164 exit($opts{'-exitval'}) unless (lc($opts{'-exitval'}) eq 'noexit');
165}
166
167##---------------------------------------------------------------------------
168
169##-------------------------------
170## Method definitions begin here
171##-------------------------------
172
173sub new {
174 my $this = shift;
175 my $class = ref($this) || $this;
176 my %params = @_;
177 my $self = {%params};
178 bless $self, $class;
179 if ($self->can('initialize')) {
180 $self->initialize();
181 } else {
182 # pass through options to Pod::Text
183 my %opts;
184 for (qw(alt code indent loose margin quotes sentence stderr utf8 width)) {
185 my $val = $params{USAGE_OPTIONS}{"-$_"};
186 $opts{$_} = $val if defined $val;
187 }
188 $self = $self->SUPER::new(%opts);
189 %$self = (%$self, %params);
190 }
191 return $self;
192}
193
194# This subroutine was copied in whole-cloth from Pod::Select 1.60 in order to
195# allow the ejection of Pod::Select from the core without breaking Pod::Usage.
196# -- rjbs, 2013-03-18
197sub _compile_section_spec {
198 my ($section_spec) = @_;
199 my (@regexs, $negated);
200
201 ## Compile the spec into a list of regexs
202 local $_ = $section_spec;
203 s{\\\\}{\001}g; ## handle escaped backward slashes
204 s{\\/}{\002}g; ## handle escaped forward slashes
205
206 ## Parse the regexs for the heading titles
207 @regexs = split(/\//, $_, $MAX_HEADING_LEVEL);
208
209 ## Set default regex for ommitted levels
210 for (my $i = 0; $i < $MAX_HEADING_LEVEL; ++$i) {
211 $regexs[$i] = '.*' unless ((defined $regexs[$i])
212 && (length $regexs[$i]));
213 }
214 ## Modify the regexs as needed and validate their syntax
215 my $bad_regexs = 0;
216 for (@regexs) {
217 $_ .= '.+' if ($_ eq '!');
218 s{\001}{\\\\}g; ## restore escaped backward slashes
219 s{\002}{\\/}g; ## restore escaped forward slashes
220 $negated = s/^\!//; ## check for negation
221 eval "m{$_}"; ## check regex syntax
222 if ($@) {
223 ++$bad_regexs;
224 carp qq{Bad regular expression /$_/ in "$section_spec": $@\n};
225 }
226 else {
227 ## Add the forward and rear anchors (and put the negator back)
228 $_ = '^' . $_ unless (/^\^/);
229 $_ = $_ . '$' unless (/\$$/);
230 $_ = '!' . $_ if ($negated);
231 }
232 }
233 return (! $bad_regexs) ? [ @regexs ] : undef;
234}
235
236sub select {
237 my ($self, @sections) = @_;
238 if ($ISA[0]->can('select')) {
239 $self->SUPER::select(@sections);
240 } else {
241 # we're using Pod::Simple - need to mimic the behavior of Pod::Select
242 my $add = ($sections[0] eq '+') ? shift(@sections) : '';
243 ## Reset the set of sections to use
244 unless (@sections) {
245 delete $self->{USAGE_SELECT} unless ($add);
246 return;
247 }
248 $self->{USAGE_SELECT} = []
249 unless ($add && $self->{USAGE_SELECT});
250 my $sref = $self->{USAGE_SELECT};
251 ## Compile each spec
252 for my $spec (@sections) {
253 my $cs = _compile_section_spec($spec);
254 if ( defined $cs ) {
255 ## Store them in our sections array
256 push(@$sref, $cs);
257 } else {
258 carp qq{Ignoring section spec "$spec"!\n};
259 }
260 }
261 }
262}
263
264# Override Pod::Text->seq_i to return just "arg", not "*arg*".
265sub seq_i { return $_[1] }
266
267# This overrides the Pod::Text method to do something very akin to what
268# Pod::Select did as well as the work done below by preprocess_paragraph.
269# Note that the below is very, very specific to Pod::Text.
270sub _handle_element_end {
271 my ($self, $element) = @_;
272 if ($element eq 'head1') {
273 $self->{USAGE_HEADINGS} = [ $$self{PENDING}[-1][1] ];
274 if ($self->{USAGE_OPTIONS}->{-verbose} < 2) {
275 $$self{PENDING}[-1][1] =~ s/^\s*SYNOPSIS\s*$/USAGE/;
276 }
277 } elsif ($element =~ /^head(\d+)$/ && $1) { # avoid 0
278 my $idx = $1 - 1;
279 $self->{USAGE_HEADINGS} = [] unless($self->{USAGE_HEADINGS});
280 $self->{USAGE_HEADINGS}->[$idx] = $$self{PENDING}[-1][1];
281 }
282 if ($element =~ /^head\d+$/) {
283 $$self{USAGE_SKIPPING} = 1;
284 if (!$$self{USAGE_SELECT} || !@{ $$self{USAGE_SELECT} }) {
285 $$self{USAGE_SKIPPING} = 0;
286 } else {
287 my @headings = @{$$self{USAGE_HEADINGS}};
288 for my $section_spec ( @{$$self{USAGE_SELECT}} ) {
289 my $match = 1;
290 for (my $i = 0; $i < $MAX_HEADING_LEVEL; ++$i) {
291 $headings[$i] = '' unless defined $headings[$i];
292 my $regex = $section_spec->[$i];
293 my $negated = ($regex =~ s/^\!//);
294 $match &= ($negated ? ($headings[$i] !~ /${regex}/)
295 : ($headings[$i] =~ /${regex}/));
296 last unless ($match);
297 } # end heading levels
298 if ($match) {
299 $$self{USAGE_SKIPPING} = 0;
300 last;
301 }
302 } # end sections
303 }
304
305 # Try to do some lowercasing instead of all-caps in headings, and use
306 # a colon to end all headings.
307 if($self->{USAGE_OPTIONS}->{-verbose} < 2) {
308 local $_ = $$self{PENDING}[-1][1];
309 s{([A-Z])([A-Z]+)}{((length($2) > 2) ? $1 : lc($1)) . lc($2)}ge;
310 s/\s*$/:/ unless (/:\s*$/);
311 $_ .= "\n";
312 $$self{PENDING}[-1][1] = $_;
313 }
314 }
315 if ($$self{USAGE_SKIPPING} && $element !~ m/^over-/) {
316 pop @{ $$self{PENDING} };
317 } else {
318 $self->SUPER::_handle_element_end($element);
319 }
320}
321
322# required for Pod::Simple API
323sub start_document {
324 my $self = shift;
325 $self->SUPER::start_document();
326 my $msg = $self->{USAGE_OPTIONS}->{-message} or return 1;
327 my $out_fh = $self->output_fh();
328 print $out_fh "$msg\n";
329}
330
331# required for old Pod::Parser API
332sub begin_pod {
333 my $self = shift;
334 $self->SUPER::begin_pod(); ## Have to call superclass
335 my $msg = $self->{USAGE_OPTIONS}->{-message} or return 1;
336 my $out_fh = $self->output_handle();
337 print $out_fh "$msg\n";
338}
339
340sub preprocess_paragraph {
341 my $self = shift;
342 local $_ = shift;
343 my $line = shift;
2ed39982 344 ## See if this is a heading and we aren't printing the entire manpage.
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345 if (($self->{USAGE_OPTIONS}->{-verbose} < 2) && /^=head/) {
346 ## Change the title of the SYNOPSIS section to USAGE
347 s/^=head1\s+SYNOPSIS\s*$/=head1 USAGE/;
348 ## Try to do some lowercasing instead of all-caps in headings
349 s{([A-Z])([A-Z]+)}{((length($2) > 2) ? $1 : lc($1)) . lc($2)}ge;
350 ## Use a colon to end all headings
351 s/\s*$/:/ unless (/:\s*$/);
352 $_ .= "\n";
353 }
354 return $self->SUPER::preprocess_paragraph($_);
355}
356
3571; # keep require happy
358
359__END__
360
361=head1 NAME
362
363Pod::Usage, pod2usage() - print a usage message from embedded pod documentation
364
365=head1 SYNOPSIS
366
367 use Pod::Usage
368
369 my $message_text = "This text precedes the usage message.";
370 my $exit_status = 2; ## The exit status to use
371 my $verbose_level = 0; ## The verbose level to use
372 my $filehandle = \*STDERR; ## The filehandle to write to
373
374 pod2usage($message_text);
375
376 pod2usage($exit_status);
377
378 pod2usage( { -message => $message_text ,
379 -exitval => $exit_status ,
380 -verbose => $verbose_level,
381 -output => $filehandle } );
382
383 pod2usage( -msg => $message_text ,
384 -exitval => $exit_status ,
385 -verbose => $verbose_level,
386 -output => $filehandle );
387
388 pod2usage( -verbose => 2,
389 -noperldoc => 1 )
390
391=head1 ARGUMENTS
392
393B<pod2usage> should be given either a single argument, or a list of
394arguments corresponding to an associative array (a "hash"). When a single
395argument is given, it should correspond to exactly one of the following:
396
397=over 4
398
399=item *
400
401A string containing the text of a message to print I<before> printing
402the usage message
403
404=item *
405
406A numeric value corresponding to the desired exit status
407
408=item *
409
410A reference to a hash
411
412=back
413
414If more than one argument is given then the entire argument list is
415assumed to be a hash. If a hash is supplied (either as a reference or
416as a list) it should contain one or more elements with the following
417keys:
418
419=over 4
420
421=item C<-message>
422
423=item C<-msg>
424
425The text of a message to print immediately prior to printing the
426program's usage message.
427
428=item C<-exitval>
429
430The desired exit status to pass to the B<exit()> function.
431This should be an integer, or else the string "NOEXIT" to
432indicate that control should simply be returned without
433terminating the invoking process.
434
435=item C<-verbose>
436
437The desired level of "verboseness" to use when printing the usage
438message. If the corresponding value is 0, then only the "SYNOPSIS"
439section of the pod documentation is printed. If the corresponding value
440is 1, then the "SYNOPSIS" section, along with any section entitled
441"OPTIONS", "ARGUMENTS", or "OPTIONS AND ARGUMENTS" is printed. If the
442corresponding value is 2 or more then the entire manpage is printed.
443
444The special verbosity level 99 requires to also specify the -sections
445parameter; then these sections are extracted and printed.
446
447=item C<-sections>
448
449A string representing a selection list for sections to be printed
450when -verbose is set to 99, e.g. C<"NAME|SYNOPSIS|DESCRIPTION|VERSION">.
451
452Alternatively, an array reference of section specifications can be used:
453
454 pod2usage(-verbose => 99,
455 -sections => [ qw(fred fred/subsection) ] );
456
457=item C<-output>
458
459A reference to a filehandle, or the pathname of a file to which the
460usage message should be written. The default is C<\*STDERR> unless the
461exit value is less than 2 (in which case the default is C<\*STDOUT>).
462
463=item C<-input>
464
465A reference to a filehandle, or the pathname of a file from which the
466invoking script's pod documentation should be read. It defaults to the
467file indicated by C<$0> (C<$PROGRAM_NAME> for users of F<English.pm>).
468
469If you are calling B<pod2usage()> from a module and want to display
470that module's POD, you can use this:
471
472 use Pod::Find qw(pod_where);
473 pod2usage( -input => pod_where({-inc => 1}, __PACKAGE__) );
474
475=item C<-pathlist>
476
477A list of directory paths. If the input file does not exist, then it
478will be searched for in the given directory list (in the order the
479directories appear in the list). It defaults to the list of directories
480implied by C<$ENV{PATH}>. The list may be specified either by a reference
481to an array, or by a string of directory paths which use the same path
482separator as C<$ENV{PATH}> on your system (e.g., C<:> for Unix, C<;> for
483MSWin32 and DOS).
484
485=item C<-noperldoc>
486
487By default, Pod::Usage will call L<perldoc> when -verbose >= 2 is
488specified. This does not work well e.g. if the script was packed
489with L<PAR>. The -noperldoc option suppresses the external call to
490L<perldoc> and uses the simple text formatter (L<Pod::Text>) to
491output the POD.
492
493=back
494
495=head2 Formatting base class
496
497The default text formatter is L<Pod::Text>. The base class for Pod::Usage can
498be defined by pre-setting C<$Pod::Usage::Formatter> I<before>
499loading Pod::Usage, e.g.:
500
501 BEGIN { $Pod::Usage::Formatter = 'Pod::Text::Termcap'; }
502 use Pod::Usage qw(pod2usage);
503
504=head2 Pass-through options
505
506The following options are passed through to the underlying text formatter.
507See the manual pages of these modules for more information.
508
509 alt code indent loose margin quotes sentence stderr utf8 width
510
511=head1 DESCRIPTION
512
513B<pod2usage> will print a usage message for the invoking script (using
514its embedded pod documentation) and then exit the script with the
515desired exit status. The usage message printed may have any one of three
516levels of "verboseness": If the verbose level is 0, then only a synopsis
517is printed. If the verbose level is 1, then the synopsis is printed
518along with a description (if present) of the command line options and
519arguments. If the verbose level is 2, then the entire manual page is
520printed.
521
522Unless they are explicitly specified, the default values for the exit
523status, verbose level, and output stream to use are determined as
524follows:
525
526=over 4
527
528=item *
529
530If neither the exit status nor the verbose level is specified, then the
531default is to use an exit status of 2 with a verbose level of 0.
532
533=item *
534
535If an exit status I<is> specified but the verbose level is I<not>, then the
536verbose level will default to 1 if the exit status is less than 2 and
537will default to 0 otherwise.
538
539=item *
540
541If an exit status is I<not> specified but verbose level I<is> given, then
542the exit status will default to 2 if the verbose level is 0 and will
543default to 1 otherwise.
544
545=item *
546
547If the exit status used is less than 2, then output is printed on
548C<STDOUT>. Otherwise output is printed on C<STDERR>.
549
550=back
551
552Although the above may seem a bit confusing at first, it generally does
553"the right thing" in most situations. This determination of the default
554values to use is based upon the following typical Unix conventions:
555
556=over 4
557
558=item *
559
560An exit status of 0 implies "success". For example, B<diff(1)> exits
561with a status of 0 if the two files have the same contents.
562
563=item *
564
565An exit status of 1 implies possibly abnormal, but non-defective, program
566termination. For example, B<grep(1)> exits with a status of 1 if
567it did I<not> find a matching line for the given regular expression.
568
569=item *
570
571An exit status of 2 or more implies a fatal error. For example, B<ls(1)>
572exits with a status of 2 if you specify an illegal (unknown) option on
573the command line.
574
575=item *
576
577Usage messages issued as a result of bad command-line syntax should go
578to C<STDERR>. However, usage messages issued due to an explicit request
579to print usage (like specifying B<-help> on the command line) should go
580to C<STDOUT>, just in case the user wants to pipe the output to a pager
581(such as B<more(1)>).
582
583=item *
584
585If program usage has been explicitly requested by the user, it is often
586desirable to exit with a status of 1 (as opposed to 0) after issuing
587the user-requested usage message. It is also desirable to give a
588more verbose description of program usage in this case.
589
590=back
591
592B<pod2usage> doesn't force the above conventions upon you, but it will
593use them by default if you don't expressly tell it to do otherwise. The
594ability of B<pod2usage()> to accept a single number or a string makes it
595convenient to use as an innocent looking error message handling function:
596
597 use Pod::Usage;
598 use Getopt::Long;
599
600 ## Parse options
601 GetOptions("help", "man", "flag1") || pod2usage(2);
602 pod2usage(1) if ($opt_help);
603 pod2usage(-verbose => 2) if ($opt_man);
604
605 ## Check for too many filenames
606 pod2usage("$0: Too many files given.\n") if (@ARGV > 1);
607
608Some user's however may feel that the above "economy of expression" is
609not particularly readable nor consistent and may instead choose to do
610something more like the following:
611
612 use Pod::Usage;
613 use Getopt::Long;
614
615 ## Parse options
616 GetOptions("help", "man", "flag1") || pod2usage(-verbose => 0);
617 pod2usage(-verbose => 1) if ($opt_help);
618 pod2usage(-verbose => 2) if ($opt_man);
619
620 ## Check for too many filenames
621 pod2usage(-verbose => 2, -message => "$0: Too many files given.\n")
622 if (@ARGV > 1);
623
624As with all things in Perl, I<there's more than one way to do it>, and
625B<pod2usage()> adheres to this philosophy. If you are interested in
626seeing a number of different ways to invoke B<pod2usage> (although by no
627means exhaustive), please refer to L<"EXAMPLES">.
628
629=head1 EXAMPLES
630
631Each of the following invocations of C<pod2usage()> will print just the
632"SYNOPSIS" section to C<STDERR> and will exit with a status of 2:
633
634 pod2usage();
635
636 pod2usage(2);
637
638 pod2usage(-verbose => 0);
639
640 pod2usage(-exitval => 2);
641
642 pod2usage({-exitval => 2, -output => \*STDERR});
643
644 pod2usage({-verbose => 0, -output => \*STDERR});
645
646 pod2usage(-exitval => 2, -verbose => 0);
647
648 pod2usage(-exitval => 2, -verbose => 0, -output => \*STDERR);
649
650Each of the following invocations of C<pod2usage()> will print a message
651of "Syntax error." (followed by a newline) to C<STDERR>, immediately
652followed by just the "SYNOPSIS" section (also printed to C<STDERR>) and
653will exit with a status of 2:
654
655 pod2usage("Syntax error.");
656
657 pod2usage(-message => "Syntax error.", -verbose => 0);
658
659 pod2usage(-msg => "Syntax error.", -exitval => 2);
660
661 pod2usage({-msg => "Syntax error.", -exitval => 2, -output => \*STDERR});
662
663 pod2usage({-msg => "Syntax error.", -verbose => 0, -output => \*STDERR});
664
665 pod2usage(-msg => "Syntax error.", -exitval => 2, -verbose => 0);
666
667 pod2usage(-message => "Syntax error.",
668 -exitval => 2,
669 -verbose => 0,
670 -output => \*STDERR);
671
672Each of the following invocations of C<pod2usage()> will print the
673"SYNOPSIS" section and any "OPTIONS" and/or "ARGUMENTS" sections to
674C<STDOUT> and will exit with a status of 1:
675
676 pod2usage(1);
677
678 pod2usage(-verbose => 1);
679
680 pod2usage(-exitval => 1);
681
682 pod2usage({-exitval => 1, -output => \*STDOUT});
683
684 pod2usage({-verbose => 1, -output => \*STDOUT});
685
686 pod2usage(-exitval => 1, -verbose => 1);
687
688 pod2usage(-exitval => 1, -verbose => 1, -output => \*STDOUT});
689
690Each of the following invocations of C<pod2usage()> will print the
691entire manual page to C<STDOUT> and will exit with a status of 1:
692
693 pod2usage(-verbose => 2);
694
695 pod2usage({-verbose => 2, -output => \*STDOUT});
696
697 pod2usage(-exitval => 1, -verbose => 2);
698
699 pod2usage({-exitval => 1, -verbose => 2, -output => \*STDOUT});
700
701=head2 Recommended Use
702
703Most scripts should print some type of usage message to C<STDERR> when a
704command line syntax error is detected. They should also provide an
705option (usually C<-H> or C<-help>) to print a (possibly more verbose)
706usage message to C<STDOUT>. Some scripts may even wish to go so far as to
707provide a means of printing their complete documentation to C<STDOUT>
708(perhaps by allowing a C<-man> option). The following complete example
709uses B<Pod::Usage> in combination with B<Getopt::Long> to do all of these
710things:
711
712 use Getopt::Long;
713 use Pod::Usage;
714
715 my $man = 0;
716 my $help = 0;
717 ## Parse options and print usage if there is a syntax error,
718 ## or if usage was explicitly requested.
719 GetOptions('help|?' => \$help, man => \$man) or pod2usage(2);
720 pod2usage(1) if $help;
721 pod2usage(-verbose => 2) if $man;
722
723 ## If no arguments were given, then allow STDIN to be used only
724 ## if it's not connected to a terminal (otherwise print usage)
725 pod2usage("$0: No files given.") if ((@ARGV == 0) && (-t STDIN));
726 __END__
727
728 =head1 NAME
729
730 sample - Using GetOpt::Long and Pod::Usage
731
732 =head1 SYNOPSIS
733
734 sample [options] [file ...]
735
736 Options:
737 -help brief help message
738 -man full documentation
739
740 =head1 OPTIONS
741
742 =over 8
743
744 =item B<-help>
745
746 Print a brief help message and exits.
747
748 =item B<-man>
749
750 Prints the manual page and exits.
751
752 =back
753
754 =head1 DESCRIPTION
755
756 B<This program> will read the given input file(s) and do something
757 useful with the contents thereof.
758
759 =cut
760
761=head1 CAVEATS
762
763By default, B<pod2usage()> will use C<$0> as the path to the pod input
764file. Unfortunately, not all systems on which Perl runs will set C<$0>
765properly (although if C<$0> isn't found, B<pod2usage()> will search
766C<$ENV{PATH}> or else the list specified by the C<-pathlist> option).
767If this is the case for your system, you may need to explicitly specify
768the path to the pod docs for the invoking script using something
769similar to the following:
770
771 pod2usage(-exitval => 2, -input => "/path/to/your/pod/docs");
772
773In the pathological case that a script is called via a relative path
774I<and> the script itself changes the current working directory
775(see L<perlfunc/chdir>) I<before> calling pod2usage, Pod::Usage will
776fail even on robust platforms. Don't do that. Or use L<FindBin> to locate
777the script:
778
779 use FindBin;
780 pod2usage(-input => $FindBin::Bin . "/" . $FindBin::Script);
781
782=head1 AUTHOR
783
784Please report bugs using L<http://rt.cpan.org>.
785
786Marek Rouchal E<lt>marekr@cpan.orgE<gt>
787
788Brad Appleton E<lt>bradapp@enteract.comE<gt>
789
790Based on code for B<Pod::Text::pod2text()> written by
791Tom Christiansen E<lt>tchrist@mox.perl.comE<gt>
792
793=head1 ACKNOWLEDGMENTS
794
795rjbs for refactoring Pod::Usage to not use Pod::Parser any more.
796
797Steven McDougall E<lt>swmcd@world.std.comE<gt> for his help and patience
798with re-writing this manpage.
799
800=head1 SEE ALSO
801
802B<Pod::Usage> is now a standalone distribution, depending on
803L<Pod::Text> which in turn depends on L<Pod::Simple>.
804
805L<Pod::Perldoc>, L<Getopt::Long>, L<Pod::Find>, L<FindBin>,
806L<Pod::Text>, L<Pod::Text::Termcap>, L<Pod::Simple>
807
808=cut
809