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1 | ############################################################################# |
2 | # Pod/Usage.pm -- print usage messages for the running script. | |
3 | # | |
66aff6dd | 4 | # Copyright (C) 1996-2000 by Bradford Appleton. All rights reserved. |
360aca43 GS |
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 | ||
10 | package Pod::Usage; | |
11 | ||
12 | use vars qw($VERSION); | |
828c4421 GS |
13 | $VERSION = 1.12; ## Current version of this package |
14 | require 5.005; ## requires this Perl version or later | |
360aca43 GS |
15 | |
16 | =head1 NAME | |
17 | ||
18 | Pod::Usage, pod2usage() - print a usage message from embedded pod documentation | |
19 | ||
20 | =head1 SYNOPSIS | |
21 | ||
22 | use Pod::Usage | |
23 | ||
24 | my $message_text = "This text precedes the usage message."; | |
25 | my $exit_status = 2; ## The exit status to use | |
26 | my $verbose_level = 0; ## The verbose level to use | |
27 | my $filehandle = \*STDERR; ## The filehandle to write to | |
28 | ||
29 | pod2usage($message_text); | |
30 | ||
31 | pod2usage($exit_status); | |
32 | ||
33 | pod2usage( { -message => $message_text , | |
34 | -exitval => $exit_status , | |
35 | -verbose => $verbose_level, | |
36 | -output => $filehandle } ); | |
37 | ||
38 | pod2usage( -msg => $message_text , | |
39 | -exitval => $exit_status , | |
40 | -verbose => $verbose_level, | |
41 | -output => $filehandle ); | |
42 | ||
43 | =head1 ARGUMENTS | |
44 | ||
45 | B<pod2usage> should be given either a single argument, or a list of | |
46 | arguments corresponding to an associative array (a "hash"). When a single | |
47 | argument is given, it should correspond to exactly one of the following: | |
48 | ||
49 | =over | |
50 | ||
51 | =item * | |
52 | ||
53 | A string containing the text of a message to print I<before> printing | |
54 | the usage message | |
55 | ||
56 | =item * | |
57 | ||
58 | A numeric value corresponding to the desired exit status | |
59 | ||
60 | =item * | |
61 | ||
62 | A reference to a hash | |
63 | ||
64 | =back | |
65 | ||
66 | If more than one argument is given then the entire argument list is | |
67 | assumed to be a hash. If a hash is supplied (either as a reference or | |
68 | as a list) it should contain one or more elements with the following | |
69 | keys: | |
70 | ||
71 | =over | |
72 | ||
73 | =item C<-message> | |
74 | ||
75 | =item C<-msg> | |
76 | ||
77 | The text of a message to print immediately prior to printing the | |
78 | program's usage message. | |
79 | ||
80 | =item C<-exitval> | |
81 | ||
82 | The desired exit status to pass to the B<exit()> function. | |
83 | ||
84 | =item C<-verbose> | |
85 | ||
86 | The desired level of "verboseness" to use when printing the usage | |
87 | message. If the corresponding value is 0, then only the "SYNOPSIS" | |
88 | section of the pod documentation is printed. If the corresponding value | |
89 | is 1, then the "SYNOPSIS" section, along with any section entitled | |
90 | "OPTIONS", "ARGUMENTS", or "OPTIONS AND ARGUMENTS" is printed. If the | |
91 | corresponding value is 2 or more then the entire manpage is printed. | |
92 | ||
93 | =item C<-output> | |
94 | ||
95 | A reference to a filehandle, or the pathname of a file to which the | |
96 | usage message should be written. The default is C<\*STDERR> unless the | |
97 | exit value is less than 2 (in which case the default is C<\*STDOUT>). | |
98 | ||
99 | =item C<-input> | |
100 | ||
101 | A reference to a filehandle, or the pathname of a file from which the | |
102 | invoking script's pod documentation should be read. It defaults to the | |
103 | file indicated by C<$0> (C<$PROGRAM_NAME> for users of F<English.pm>). | |
104 | ||
105 | =item C<-pathlist> | |
106 | ||
107 | A list of directory paths. If the input file does not exist, then it | |
108 | will be searched for in the given directory list (in the order the | |
109 | directories appear in the list). It defaults to the list of directories | |
110 | implied by C<$ENV{PATH}>. The list may be specified either by a reference | |
111 | to an array, or by a string of directory paths which use the same path | |
112 | separator as C<$ENV{PATH}> on your system (e.g., C<:> for Unix, C<;> for | |
113 | MSWin32 and DOS). | |
114 | ||
115 | =back | |
116 | ||
117 | =head1 DESCRIPTION | |
118 | ||
119 | B<pod2usage> will print a usage message for the invoking script (using | |
120 | its embedded pod documentation) and then exit the script with the | |
121 | desired exit status. The usage message printed may have any one of three | |
122 | levels of "verboseness": If the verbose level is 0, then only a synopsis | |
123 | is printed. If the verbose level is 1, then the synopsis is printed | |
124 | along with a description (if present) of the command line options and | |
125 | arguments. If the verbose level is 2, then the entire manual page is | |
126 | printed. | |
127 | ||
128 | Unless they are explicitly specified, the default values for the exit | |
129 | status, verbose level, and output stream to use are determined as | |
130 | follows: | |
131 | ||
132 | =over | |
133 | ||
134 | =item * | |
135 | ||
136 | If neither the exit status nor the verbose level is specified, then the | |
137 | default is to use an exit status of 2 with a verbose level of 0. | |
138 | ||
139 | =item * | |
140 | ||
141 | If an exit status I<is> specified but the verbose level is I<not>, then the | |
142 | verbose level will default to 1 if the exit status is less than 2 and | |
143 | will default to 0 otherwise. | |
144 | ||
145 | =item * | |
146 | ||
147 | If an exit status is I<not> specified but verbose level I<is> given, then | |
148 | the exit status will default to 2 if the verbose level is 0 and will | |
149 | default to 1 otherwise. | |
150 | ||
151 | =item * | |
152 | ||
153 | If the exit status used is less than 2, then output is printed on | |
154 | C<STDOUT>. Otherwise output is printed on C<STDERR>. | |
155 | ||
156 | =back | |
157 | ||
158 | Although the above may seem a bit confusing at first, it generally does | |
159 | "the right thing" in most situations. This determination of the default | |
160 | values to use is based upon the following typical Unix conventions: | |
161 | ||
162 | =over | |
163 | ||
164 | =item * | |
165 | ||
166 | An exit status of 0 implies "success". For example, B<diff(1)> exits | |
167 | with a status of 0 if the two files have the same contents. | |
168 | ||
169 | =item * | |
170 | ||
171 | An exit status of 1 implies possibly abnormal, but non-defective, program | |
172 | termination. For example, B<grep(1)> exits with a status of 1 if | |
173 | it did I<not> find a matching line for the given regular expression. | |
174 | ||
175 | =item * | |
176 | ||
177 | An exit status of 2 or more implies a fatal error. For example, B<ls(1)> | |
178 | exits with a status of 2 if you specify an illegal (unknown) option on | |
179 | the command line. | |
180 | ||
181 | =item * | |
182 | ||
183 | Usage messages issued as a result of bad command-line syntax should go | |
184 | to C<STDERR>. However, usage messages issued due to an explicit request | |
185 | to print usage (like specifying B<-help> on the command line) should go | |
186 | to C<STDOUT>, just in case the user wants to pipe the output to a pager | |
187 | (such as B<more(1)>). | |
188 | ||
189 | =item * | |
190 | ||
191 | If program usage has been explicitly requested by the user, it is often | |
192 | desireable to exit with a status of 1 (as opposed to 0) after issuing | |
193 | the user-requested usage message. It is also desireable to give a | |
194 | more verbose description of program usage in this case. | |
195 | ||
196 | =back | |
197 | ||
198 | B<pod2usage> doesn't force the above conventions upon you, but it will | |
199 | use them by default if you don't expressly tell it to do otherwise. The | |
200 | ability of B<pod2usage()> to accept a single number or a string makes it | |
201 | convenient to use as an innocent looking error message handling function: | |
202 | ||
203 | use Pod::Usage; | |
204 | use Getopt::Long; | |
205 | ||
206 | ## Parse options | |
207 | GetOptions("help", "man", "flag1") || pod2usage(2); | |
208 | pod2usage(1) if ($opt_help); | |
209 | pod2usage(-verbose => 2) if ($opt_man); | |
210 | ||
211 | ## Check for too many filenames | |
212 | pod2usage("$0: Too many files given.\n") if (@ARGV > 1); | |
213 | ||
6940069f | 214 | Some users however may feel that the above "economy of expression" is |
360aca43 GS |
215 | not particularly readable nor consistent and may instead choose to do |
216 | something more like the following: | |
217 | ||
218 | use Pod::Usage; | |
219 | use Getopt::Long; | |
220 | ||
221 | ## Parse options | |
222 | GetOptions("help", "man", "flag1") || pod2usage(-verbose => 0); | |
223 | pod2usage(-verbose => 1) if ($opt_help); | |
224 | pod2usage(-verbose => 2) if ($opt_man); | |
225 | ||
226 | ## Check for too many filenames | |
227 | pod2usage(-verbose => 2, -message => "$0: Too many files given.\n") | |
228 | if (@ARGV > 1); | |
229 | ||
230 | As with all things in Perl, I<there's more than one way to do it>, and | |
231 | B<pod2usage()> adheres to this philosophy. If you are interested in | |
232 | seeing a number of different ways to invoke B<pod2usage> (although by no | |
233 | means exhaustive), please refer to L<"EXAMPLES">. | |
234 | ||
235 | =head1 EXAMPLES | |
236 | ||
237 | Each of the following invocations of C<pod2usage()> will print just the | |
238 | "SYNOPSIS" section to C<STDERR> and will exit with a status of 2: | |
239 | ||
240 | pod2usage(); | |
241 | ||
242 | pod2usage(2); | |
243 | ||
244 | pod2usage(-verbose => 0); | |
245 | ||
246 | pod2usage(-exitval => 2); | |
247 | ||
248 | pod2usage({-exitval => 2, -output => \*STDERR}); | |
249 | ||
250 | pod2usage({-verbose => 0, -output => \*STDERR}); | |
251 | ||
252 | pod2usage(-exitval => 2, -verbose => 0); | |
253 | ||
254 | pod2usage(-exitval => 2, -verbose => 0, -output => \*STDERR); | |
255 | ||
256 | Each of the following invocations of C<pod2usage()> will print a message | |
257 | of "Syntax error." (followed by a newline) to C<STDERR>, immediately | |
258 | followed by just the "SYNOPSIS" section (also printed to C<STDERR>) and | |
259 | will exit with a status of 2: | |
260 | ||
261 | pod2usage("Syntax error."); | |
262 | ||
263 | pod2usage(-message => "Syntax error.", -verbose => 0); | |
264 | ||
265 | pod2usage(-msg => "Syntax error.", -exitval => 2); | |
266 | ||
267 | pod2usage({-msg => "Syntax error.", -exitval => 2, -output => \*STDERR}); | |
268 | ||
269 | pod2usage({-msg => "Syntax error.", -verbose => 0, -output => \*STDERR}); | |
270 | ||
271 | pod2usage(-msg => "Syntax error.", -exitval => 2, -verbose => 0); | |
272 | ||
273 | pod2usage(-message => "Syntax error.", | |
274 | -exitval => 2, | |
275 | -verbose => 0, | |
276 | -output => \*STDERR); | |
277 | ||
278 | Each of the following invocations of C<pod2usage()> will print the | |
279 | "SYNOPSIS" section and any "OPTIONS" and/or "ARGUMENTS" sections to | |
280 | C<STDOUT> and will exit with a status of 1: | |
281 | ||
282 | pod2usage(1); | |
283 | ||
284 | pod2usage(-verbose => 1); | |
285 | ||
286 | pod2usage(-exitval => 1); | |
287 | ||
288 | pod2usage({-exitval => 1, -output => \*STDOUT}); | |
289 | ||
290 | pod2usage({-verbose => 1, -output => \*STDOUT}); | |
291 | ||
292 | pod2usage(-exitval => 1, -verbose => 1); | |
293 | ||
294 | pod2usage(-exitval => 1, -verbose => 1, -output => \*STDOUT}); | |
295 | ||
296 | Each of the following invocations of C<pod2usage()> will print the | |
297 | entire manual page to C<STDOUT> and will exit with a status of 1: | |
298 | ||
299 | pod2usage(-verbose => 2); | |
300 | ||
301 | pod2usage({-verbose => 2, -output => \*STDOUT}); | |
302 | ||
303 | pod2usage(-exitval => 1, -verbose => 2); | |
304 | ||
305 | pod2usage({-exitval => 1, -verbose => 2, -output => \*STDOUT}); | |
306 | ||
307 | =head2 Recommended Use | |
308 | ||
309 | Most scripts should print some type of usage message to C<STDERR> when a | |
310 | command line syntax error is detected. They should also provide an | |
311 | option (usually C<-H> or C<-help>) to print a (possibly more verbose) | |
312 | usage message to C<STDOUT>. Some scripts may even wish to go so far as to | |
313 | provide a means of printing their complete documentation to C<STDOUT> | |
f48e6a7e GS |
314 | (perhaps by allowing a C<-man> option). The following complete example |
315 | uses B<Pod::Usage> in combination with B<Getopt::Long> to do all of these | |
360aca43 GS |
316 | things: |
317 | ||
318 | use Getopt::Long; | |
319 | use Pod::Usage; | |
320 | ||
f48e6a7e GS |
321 | my $man = 0; |
322 | my $help = 0; | |
360aca43 GS |
323 | ## Parse options and print usage if there is a syntax error, |
324 | ## or if usage was explicitly requested. | |
f48e6a7e GS |
325 | GetOptions('help|?' => \$help, man => \$man) or pod2usage(2); |
326 | pod2usage(1) if $help; | |
327 | pod2usage(-verbose => 2) if $man; | |
360aca43 GS |
328 | |
329 | ## If no arguments were given, then allow STDIN to be used only | |
330 | ## if it's not connected to a terminal (otherwise print usage) | |
331 | pod2usage("$0: No files given.") if ((@ARGV == 0) && (-t STDIN)); | |
f48e6a7e GS |
332 | __END__ |
333 | ||
334 | =head1 NAME | |
335 | ||
336 | sample - Using GetOpt::Long and Pod::Usage | |
337 | ||
338 | =head1 SYNOPSIS | |
339 | ||
340 | sample [options] [file ...] | |
341 | ||
342 | Options: | |
343 | -help brief help message | |
344 | -man full documentation | |
345 | ||
346 | =head1 OPTIONS | |
347 | ||
348 | =over 8 | |
349 | ||
350 | =item B<-help> | |
351 | ||
352 | Print a brief help message and exits. | |
353 | ||
354 | =item B<-man> | |
355 | ||
356 | Prints the manual page and exits. | |
357 | ||
358 | =back | |
359 | ||
360 | =head1 DESCRIPTION | |
361 | ||
362 | B<This program> will read the given input file(s) and do something | |
363 | useful with the contents thereof. | |
364 | ||
365 | =cut | |
360aca43 GS |
366 | |
367 | =head1 CAVEATS | |
368 | ||
369 | By default, B<pod2usage()> will use C<$0> as the path to the pod input | |
370 | file. Unfortunately, not all systems on which Perl runs will set C<$0> | |
371 | properly (although if C<$0> isn't found, B<pod2usage()> will search | |
372 | C<$ENV{PATH}> or else the list specified by the C<-pathlist> option). | |
373 | If this is the case for your system, you may need to explicitly specify | |
374 | the path to the pod docs for the invoking script using something | |
375 | similar to the following: | |
376 | ||
377 | pod2usage(-exitval => 2, -input => "/path/to/your/pod/docs"); | |
378 | ||
379 | =head1 AUTHOR | |
380 | ||
381 | Brad Appleton E<lt>bradapp@enteract.comE<gt> | |
382 | ||
383 | Based on code for B<Pod::Text::pod2text()> written by | |
384 | Tom Christiansen E<lt>tchrist@mox.perl.comE<gt> | |
385 | ||
386 | =head1 ACKNOWLEDGEMENTS | |
387 | ||
388 | Steven McDougall E<lt>swmcd@world.std.comE<gt> for his help and patience | |
389 | with re-writing this manpage. | |
390 | ||
391 | =cut | |
392 | ||
393 | ############################################################################# | |
394 | ||
395 | use strict; | |
396 | #use diagnostics; | |
397 | use Carp; | |
398 | use Exporter; | |
360aca43 GS |
399 | use File::Spec; |
400 | ||
401 | use vars qw(@ISA @EXPORT); | |
360aca43 | 402 | @EXPORT = qw(&pod2usage); |
664bb207 GS |
403 | BEGIN { |
404 | if ( $] >= 5.005_58 ) { | |
405 | require Pod::Text; | |
406 | @ISA = qw( Pod::Text ); | |
407 | } | |
408 | else { | |
409 | require Pod::PlainText; | |
410 | @ISA = qw( Pod::PlainText ); | |
411 | } | |
412 | } | |
413 | ||
360aca43 GS |
414 | |
415 | ##--------------------------------------------------------------------------- | |
416 | ||
417 | ##--------------------------------- | |
418 | ## Function definitions begin here | |
419 | ##--------------------------------- | |
420 | ||
421 | sub pod2usage { | |
422 | local($_) = shift || ""; | |
423 | my %opts; | |
424 | ## Collect arguments | |
425 | if (@_ > 0) { | |
426 | ## Too many arguments - assume that this is a hash and | |
427 | ## the user forgot to pass a reference to it. | |
428 | %opts = ($_, @_); | |
429 | } | |
430 | elsif (ref $_) { | |
431 | ## User passed a ref to a hash | |
432 | %opts = %{$_} if (ref($_) eq 'HASH'); | |
433 | } | |
e9fdc7d2 | 434 | elsif (/^[-+]?\d+$/) { |
360aca43 GS |
435 | ## User passed in the exit value to use |
436 | $opts{"-exitval"} = $_; | |
437 | } | |
438 | else { | |
439 | ## User passed in a message to print before issuing usage. | |
440 | $_ and $opts{"-message"} = $_; | |
441 | } | |
442 | ||
443 | ## Need this for backward compatibility since we formerly used | |
444 | ## options that were all uppercase words rather than ones that | |
445 | ## looked like Unix command-line options. | |
446 | ## to be uppercase keywords) | |
447 | %opts = map { | |
448 | my $val = $opts{$_}; | |
449 | s/^(?=\w)/-/; | |
450 | /^-msg/i and $_ = '-message'; | |
451 | /^-exit/i and $_ = '-exitval'; | |
452 | lc($_) => $val; | |
453 | } (keys %opts); | |
454 | ||
455 | ## Now determine default -exitval and -verbose values to use | |
456 | if ((! defined $opts{"-exitval"}) && (! defined $opts{"-verbose"})) { | |
457 | $opts{"-exitval"} = 2; | |
458 | $opts{"-verbose"} = 0; | |
459 | } | |
460 | elsif (! defined $opts{"-exitval"}) { | |
461 | $opts{"-exitval"} = ($opts{"-verbose"} > 0) ? 1 : 2; | |
462 | } | |
463 | elsif (! defined $opts{"-verbose"}) { | |
464 | $opts{"-verbose"} = ($opts{"-exitval"} < 2); | |
465 | } | |
466 | ||
467 | ## Default the output file | |
468 | $opts{"-output"} = ($opts{"-exitval"} < 2) ? \*STDOUT : \*STDERR | |
469 | unless (defined $opts{"-output"}); | |
470 | ## Default the input file | |
471 | $opts{"-input"} = $0 unless (defined $opts{"-input"}); | |
472 | ||
473 | ## Look up input file in path if it doesnt exist. | |
474 | unless ((ref $opts{"-input"}) || (-e $opts{"-input"})) { | |
475 | my ($dirname, $basename) = ('', $opts{"-input"}); | |
476 | my $pathsep = ($^O =~ /^(?:dos|os2|MSWin32)$/) ? ";" | |
477 | : (($^O eq 'MacOS') ? ',' : ":"); | |
478 | my $pathspec = $opts{"-pathlist"} || $ENV{PATH} || $ENV{PERL5LIB}; | |
479 | ||
480 | my @paths = (ref $pathspec) ? @$pathspec : split($pathsep, $pathspec); | |
481 | for $dirname (@paths) { | |
482 | $_ = File::Spec->catfile($dirname, $basename) if length; | |
483 | last if (-e $_) && ($opts{"-input"} = $_); | |
484 | } | |
485 | } | |
486 | ||
487 | ## Now create a pod reader and constrain it to the desired sections. | |
488 | my $parser = new Pod::Usage(USAGE_OPTIONS => \%opts); | |
489 | if ($opts{"-verbose"} == 0) { | |
490 | $parser->select("SYNOPSIS"); | |
491 | } | |
492 | elsif ($opts{"-verbose"} == 1) { | |
493 | my $opt_re = '(?i)' . | |
494 | '(?:OPTIONS|ARGUMENTS)' . | |
495 | '(?:\s*(?:AND|\/)\s*(?:OPTIONS|ARGUMENTS))?'; | |
496 | $parser->select( 'SYNOPSIS', $opt_re, "DESCRIPTION/$opt_re" ); | |
497 | } | |
498 | ||
499 | ## Now translate the pod document and then exit with the desired status | |
500 | $parser->parse_from_file($opts{"-input"}, $opts{"-output"}); | |
501 | exit($opts{"-exitval"}); | |
502 | } | |
503 | ||
504 | ##--------------------------------------------------------------------------- | |
505 | ||
506 | ##------------------------------- | |
507 | ## Method definitions begin here | |
508 | ##------------------------------- | |
509 | ||
510 | sub new { | |
511 | my $this = shift; | |
512 | my $class = ref($this) || $this; | |
513 | my %params = @_; | |
514 | my $self = {%params}; | |
515 | bless $self, $class; | |
516 | $self->initialize(); | |
517 | return $self; | |
518 | } | |
519 | ||
520 | sub begin_pod { | |
521 | my $self = shift; | |
522 | $self->SUPER::begin_pod(); ## Have to call superclass | |
523 | my $msg = $self->{USAGE_OPTIONS}->{-message} or return 1; | |
524 | my $out_fh = $self->output_handle(); | |
525 | print $out_fh "$msg\n"; | |
526 | } | |
527 | ||
528 | sub preprocess_paragraph { | |
529 | my $self = shift; | |
530 | local $_ = shift; | |
531 | my $line = shift; | |
532 | ## See if this is a heading and we arent printing the entire manpage. | |
e9fdc7d2 | 533 | if (($self->{USAGE_OPTIONS}->{-verbose} < 2) && /^=head/) { |
360aca43 | 534 | ## Change the title of the SYNOPSIS section to USAGE |
e9fdc7d2 | 535 | s/^=head1\s+SYNOPSIS\s*$/=head1 USAGE/; |
360aca43 GS |
536 | ## Try to do some lowercasing instead of all-caps in headings |
537 | s{([A-Z])([A-Z]+)}{((length($2) > 2) ? $1 : lc($1)) . lc($2)}ge; | |
538 | ## Use a colon to end all headings | |
e9fdc7d2 | 539 | s/\s*$/:/ unless (/:\s*$/); |
360aca43 GS |
540 | $_ .= "\n"; |
541 | } | |
542 | return $self->SUPER::preprocess_paragraph($_); | |
543 | } | |
544 |