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1 | ############################################################################# |
2 | # Pod/Usage.pm -- print usage messages for the running script. |
3 | # |
4 | # Based on Tom Christiansen's Pod::Text::pod2text() function |
5 | # (with modifications). |
6 | # |
7 | # Copyright (C) 1994-1999 Tom Christiansen. All rights reserved. |
8 | # This file is part of "PodParser". PodParser is free software; |
9 | # you can redistribute it and/or modify it under the same terms |
10 | # as Perl itself. |
11 | ############################################################################# |
12 | |
13 | package Pod::Usage; |
14 | |
15 | use vars qw($VERSION); |
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16 | $VERSION = 1.081; ## Current version of this package |
360aca43 |
17 | require 5.004; ## requires this Perl version or later |
18 | |
19 | =head1 NAME |
20 | |
21 | Pod::Usage, pod2usage() - print a usage message from embedded pod documentation |
22 | |
23 | =head1 SYNOPSIS |
24 | |
25 | use Pod::Usage |
26 | |
27 | my $message_text = "This text precedes the usage message."; |
28 | my $exit_status = 2; ## The exit status to use |
29 | my $verbose_level = 0; ## The verbose level to use |
30 | my $filehandle = \*STDERR; ## The filehandle to write to |
31 | |
32 | pod2usage($message_text); |
33 | |
34 | pod2usage($exit_status); |
35 | |
36 | pod2usage( { -message => $message_text , |
37 | -exitval => $exit_status , |
38 | -verbose => $verbose_level, |
39 | -output => $filehandle } ); |
40 | |
41 | pod2usage( -msg => $message_text , |
42 | -exitval => $exit_status , |
43 | -verbose => $verbose_level, |
44 | -output => $filehandle ); |
45 | |
46 | =head1 ARGUMENTS |
47 | |
48 | B<pod2usage> should be given either a single argument, or a list of |
49 | arguments corresponding to an associative array (a "hash"). When a single |
50 | argument is given, it should correspond to exactly one of the following: |
51 | |
52 | =over |
53 | |
54 | =item * |
55 | |
56 | A string containing the text of a message to print I<before> printing |
57 | the usage message |
58 | |
59 | =item * |
60 | |
61 | A numeric value corresponding to the desired exit status |
62 | |
63 | =item * |
64 | |
65 | A reference to a hash |
66 | |
67 | =back |
68 | |
69 | If more than one argument is given then the entire argument list is |
70 | assumed to be a hash. If a hash is supplied (either as a reference or |
71 | as a list) it should contain one or more elements with the following |
72 | keys: |
73 | |
74 | =over |
75 | |
76 | =item C<-message> |
77 | |
78 | =item C<-msg> |
79 | |
80 | The text of a message to print immediately prior to printing the |
81 | program's usage message. |
82 | |
83 | =item C<-exitval> |
84 | |
85 | The desired exit status to pass to the B<exit()> function. |
86 | |
87 | =item C<-verbose> |
88 | |
89 | The desired level of "verboseness" to use when printing the usage |
90 | message. If the corresponding value is 0, then only the "SYNOPSIS" |
91 | section of the pod documentation is printed. If the corresponding value |
92 | is 1, then the "SYNOPSIS" section, along with any section entitled |
93 | "OPTIONS", "ARGUMENTS", or "OPTIONS AND ARGUMENTS" is printed. If the |
94 | corresponding value is 2 or more then the entire manpage is printed. |
95 | |
96 | =item C<-output> |
97 | |
98 | A reference to a filehandle, or the pathname of a file to which the |
99 | usage message should be written. The default is C<\*STDERR> unless the |
100 | exit value is less than 2 (in which case the default is C<\*STDOUT>). |
101 | |
102 | =item C<-input> |
103 | |
104 | A reference to a filehandle, or the pathname of a file from which the |
105 | invoking script's pod documentation should be read. It defaults to the |
106 | file indicated by C<$0> (C<$PROGRAM_NAME> for users of F<English.pm>). |
107 | |
108 | =item C<-pathlist> |
109 | |
110 | A list of directory paths. If the input file does not exist, then it |
111 | will be searched for in the given directory list (in the order the |
112 | directories appear in the list). It defaults to the list of directories |
113 | implied by C<$ENV{PATH}>. The list may be specified either by a reference |
114 | to an array, or by a string of directory paths which use the same path |
115 | separator as C<$ENV{PATH}> on your system (e.g., C<:> for Unix, C<;> for |
116 | MSWin32 and DOS). |
117 | |
118 | =back |
119 | |
120 | =head1 DESCRIPTION |
121 | |
122 | B<pod2usage> will print a usage message for the invoking script (using |
123 | its embedded pod documentation) and then exit the script with the |
124 | desired exit status. The usage message printed may have any one of three |
125 | levels of "verboseness": If the verbose level is 0, then only a synopsis |
126 | is printed. If the verbose level is 1, then the synopsis is printed |
127 | along with a description (if present) of the command line options and |
128 | arguments. If the verbose level is 2, then the entire manual page is |
129 | printed. |
130 | |
131 | Unless they are explicitly specified, the default values for the exit |
132 | status, verbose level, and output stream to use are determined as |
133 | follows: |
134 | |
135 | =over |
136 | |
137 | =item * |
138 | |
139 | If neither the exit status nor the verbose level is specified, then the |
140 | default is to use an exit status of 2 with a verbose level of 0. |
141 | |
142 | =item * |
143 | |
144 | If an exit status I<is> specified but the verbose level is I<not>, then the |
145 | verbose level will default to 1 if the exit status is less than 2 and |
146 | will default to 0 otherwise. |
147 | |
148 | =item * |
149 | |
150 | If an exit status is I<not> specified but verbose level I<is> given, then |
151 | the exit status will default to 2 if the verbose level is 0 and will |
152 | default to 1 otherwise. |
153 | |
154 | =item * |
155 | |
156 | If the exit status used is less than 2, then output is printed on |
157 | C<STDOUT>. Otherwise output is printed on C<STDERR>. |
158 | |
159 | =back |
160 | |
161 | Although the above may seem a bit confusing at first, it generally does |
162 | "the right thing" in most situations. This determination of the default |
163 | values to use is based upon the following typical Unix conventions: |
164 | |
165 | =over |
166 | |
167 | =item * |
168 | |
169 | An exit status of 0 implies "success". For example, B<diff(1)> exits |
170 | with a status of 0 if the two files have the same contents. |
171 | |
172 | =item * |
173 | |
174 | An exit status of 1 implies possibly abnormal, but non-defective, program |
175 | termination. For example, B<grep(1)> exits with a status of 1 if |
176 | it did I<not> find a matching line for the given regular expression. |
177 | |
178 | =item * |
179 | |
180 | An exit status of 2 or more implies a fatal error. For example, B<ls(1)> |
181 | exits with a status of 2 if you specify an illegal (unknown) option on |
182 | the command line. |
183 | |
184 | =item * |
185 | |
186 | Usage messages issued as a result of bad command-line syntax should go |
187 | to C<STDERR>. However, usage messages issued due to an explicit request |
188 | to print usage (like specifying B<-help> on the command line) should go |
189 | to C<STDOUT>, just in case the user wants to pipe the output to a pager |
190 | (such as B<more(1)>). |
191 | |
192 | =item * |
193 | |
194 | If program usage has been explicitly requested by the user, it is often |
195 | desireable to exit with a status of 1 (as opposed to 0) after issuing |
196 | the user-requested usage message. It is also desireable to give a |
197 | more verbose description of program usage in this case. |
198 | |
199 | =back |
200 | |
201 | B<pod2usage> doesn't force the above conventions upon you, but it will |
202 | use them by default if you don't expressly tell it to do otherwise. The |
203 | ability of B<pod2usage()> to accept a single number or a string makes it |
204 | convenient to use as an innocent looking error message handling function: |
205 | |
206 | use Pod::Usage; |
207 | use Getopt::Long; |
208 | |
209 | ## Parse options |
210 | GetOptions("help", "man", "flag1") || pod2usage(2); |
211 | pod2usage(1) if ($opt_help); |
212 | pod2usage(-verbose => 2) if ($opt_man); |
213 | |
214 | ## Check for too many filenames |
215 | pod2usage("$0: Too many files given.\n") if (@ARGV > 1); |
216 | |
217 | Some user's however may feel that the above "economy of expression" is |
218 | not particularly readable nor consistent and may instead choose to do |
219 | something more like the following: |
220 | |
221 | use Pod::Usage; |
222 | use Getopt::Long; |
223 | |
224 | ## Parse options |
225 | GetOptions("help", "man", "flag1") || pod2usage(-verbose => 0); |
226 | pod2usage(-verbose => 1) if ($opt_help); |
227 | pod2usage(-verbose => 2) if ($opt_man); |
228 | |
229 | ## Check for too many filenames |
230 | pod2usage(-verbose => 2, -message => "$0: Too many files given.\n") |
231 | if (@ARGV > 1); |
232 | |
233 | As with all things in Perl, I<there's more than one way to do it>, and |
234 | B<pod2usage()> adheres to this philosophy. If you are interested in |
235 | seeing a number of different ways to invoke B<pod2usage> (although by no |
236 | means exhaustive), please refer to L<"EXAMPLES">. |
237 | |
238 | =head1 EXAMPLES |
239 | |
240 | Each of the following invocations of C<pod2usage()> will print just the |
241 | "SYNOPSIS" section to C<STDERR> and will exit with a status of 2: |
242 | |
243 | pod2usage(); |
244 | |
245 | pod2usage(2); |
246 | |
247 | pod2usage(-verbose => 0); |
248 | |
249 | pod2usage(-exitval => 2); |
250 | |
251 | pod2usage({-exitval => 2, -output => \*STDERR}); |
252 | |
253 | pod2usage({-verbose => 0, -output => \*STDERR}); |
254 | |
255 | pod2usage(-exitval => 2, -verbose => 0); |
256 | |
257 | pod2usage(-exitval => 2, -verbose => 0, -output => \*STDERR); |
258 | |
259 | Each of the following invocations of C<pod2usage()> will print a message |
260 | of "Syntax error." (followed by a newline) to C<STDERR>, immediately |
261 | followed by just the "SYNOPSIS" section (also printed to C<STDERR>) and |
262 | will exit with a status of 2: |
263 | |
264 | pod2usage("Syntax error."); |
265 | |
266 | pod2usage(-message => "Syntax error.", -verbose => 0); |
267 | |
268 | pod2usage(-msg => "Syntax error.", -exitval => 2); |
269 | |
270 | pod2usage({-msg => "Syntax error.", -exitval => 2, -output => \*STDERR}); |
271 | |
272 | pod2usage({-msg => "Syntax error.", -verbose => 0, -output => \*STDERR}); |
273 | |
274 | pod2usage(-msg => "Syntax error.", -exitval => 2, -verbose => 0); |
275 | |
276 | pod2usage(-message => "Syntax error.", |
277 | -exitval => 2, |
278 | -verbose => 0, |
279 | -output => \*STDERR); |
280 | |
281 | Each of the following invocations of C<pod2usage()> will print the |
282 | "SYNOPSIS" section and any "OPTIONS" and/or "ARGUMENTS" sections to |
283 | C<STDOUT> and will exit with a status of 1: |
284 | |
285 | pod2usage(1); |
286 | |
287 | pod2usage(-verbose => 1); |
288 | |
289 | pod2usage(-exitval => 1); |
290 | |
291 | pod2usage({-exitval => 1, -output => \*STDOUT}); |
292 | |
293 | pod2usage({-verbose => 1, -output => \*STDOUT}); |
294 | |
295 | pod2usage(-exitval => 1, -verbose => 1); |
296 | |
297 | pod2usage(-exitval => 1, -verbose => 1, -output => \*STDOUT}); |
298 | |
299 | Each of the following invocations of C<pod2usage()> will print the |
300 | entire manual page to C<STDOUT> and will exit with a status of 1: |
301 | |
302 | pod2usage(-verbose => 2); |
303 | |
304 | pod2usage({-verbose => 2, -output => \*STDOUT}); |
305 | |
306 | pod2usage(-exitval => 1, -verbose => 2); |
307 | |
308 | pod2usage({-exitval => 1, -verbose => 2, -output => \*STDOUT}); |
309 | |
310 | =head2 Recommended Use |
311 | |
312 | Most scripts should print some type of usage message to C<STDERR> when a |
313 | command line syntax error is detected. They should also provide an |
314 | option (usually C<-H> or C<-help>) to print a (possibly more verbose) |
315 | usage message to C<STDOUT>. Some scripts may even wish to go so far as to |
316 | provide a means of printing their complete documentation to C<STDOUT> |
317 | (perhaps by allowing a C<-man> option). The following example uses |
318 | B<Pod::Usage> in combination with B<Getopt::Long> to do all of these |
319 | things: |
320 | |
321 | use Getopt::Long; |
322 | use Pod::Usage; |
323 | |
324 | ## Parse options and print usage if there is a syntax error, |
325 | ## or if usage was explicitly requested. |
326 | GetOptions("help", "man", "flag1") || pod2usage(2); |
327 | pod2usage(1) if ($opt_help); |
328 | pod2usage(-verbose => 2) if ($opt_man); |
329 | |
330 | ## If no arguments were given, then allow STDIN to be used only |
331 | ## if it's not connected to a terminal (otherwise print usage) |
332 | pod2usage("$0: No files given.") if ((@ARGV == 0) && (-t STDIN)); |
333 | |
334 | =head1 CAVEATS |
335 | |
336 | By default, B<pod2usage()> will use C<$0> as the path to the pod input |
337 | file. Unfortunately, not all systems on which Perl runs will set C<$0> |
338 | properly (although if C<$0> isn't found, B<pod2usage()> will search |
339 | C<$ENV{PATH}> or else the list specified by the C<-pathlist> option). |
340 | If this is the case for your system, you may need to explicitly specify |
341 | the path to the pod docs for the invoking script using something |
342 | similar to the following: |
343 | |
344 | pod2usage(-exitval => 2, -input => "/path/to/your/pod/docs"); |
345 | |
346 | =head1 AUTHOR |
347 | |
348 | Brad Appleton E<lt>bradapp@enteract.comE<gt> |
349 | |
350 | Based on code for B<Pod::Text::pod2text()> written by |
351 | Tom Christiansen E<lt>tchrist@mox.perl.comE<gt> |
352 | |
353 | =head1 ACKNOWLEDGEMENTS |
354 | |
355 | Steven McDougall E<lt>swmcd@world.std.comE<gt> for his help and patience |
356 | with re-writing this manpage. |
357 | |
358 | =cut |
359 | |
360 | ############################################################################# |
361 | |
362 | use strict; |
363 | #use diagnostics; |
364 | use Carp; |
365 | use Exporter; |
366 | use Pod::PlainText; |
367 | use File::Spec; |
368 | |
369 | use vars qw(@ISA @EXPORT); |
370 | @ISA = qw(Pod::PlainText); |
371 | @EXPORT = qw(&pod2usage); |
372 | |
373 | ##--------------------------------------------------------------------------- |
374 | |
375 | ##--------------------------------- |
376 | ## Function definitions begin here |
377 | ##--------------------------------- |
378 | |
379 | sub pod2usage { |
380 | local($_) = shift || ""; |
381 | my %opts; |
382 | ## Collect arguments |
383 | if (@_ > 0) { |
384 | ## Too many arguments - assume that this is a hash and |
385 | ## the user forgot to pass a reference to it. |
386 | %opts = ($_, @_); |
387 | } |
388 | elsif (ref $_) { |
389 | ## User passed a ref to a hash |
390 | %opts = %{$_} if (ref($_) eq 'HASH'); |
391 | } |
e9fdc7d2 |
392 | elsif (/^[-+]?\d+$/) { |
360aca43 |
393 | ## User passed in the exit value to use |
394 | $opts{"-exitval"} = $_; |
395 | } |
396 | else { |
397 | ## User passed in a message to print before issuing usage. |
398 | $_ and $opts{"-message"} = $_; |
399 | } |
400 | |
401 | ## Need this for backward compatibility since we formerly used |
402 | ## options that were all uppercase words rather than ones that |
403 | ## looked like Unix command-line options. |
404 | ## to be uppercase keywords) |
405 | %opts = map { |
406 | my $val = $opts{$_}; |
407 | s/^(?=\w)/-/; |
408 | /^-msg/i and $_ = '-message'; |
409 | /^-exit/i and $_ = '-exitval'; |
410 | lc($_) => $val; |
411 | } (keys %opts); |
412 | |
413 | ## Now determine default -exitval and -verbose values to use |
414 | if ((! defined $opts{"-exitval"}) && (! defined $opts{"-verbose"})) { |
415 | $opts{"-exitval"} = 2; |
416 | $opts{"-verbose"} = 0; |
417 | } |
418 | elsif (! defined $opts{"-exitval"}) { |
419 | $opts{"-exitval"} = ($opts{"-verbose"} > 0) ? 1 : 2; |
420 | } |
421 | elsif (! defined $opts{"-verbose"}) { |
422 | $opts{"-verbose"} = ($opts{"-exitval"} < 2); |
423 | } |
424 | |
425 | ## Default the output file |
426 | $opts{"-output"} = ($opts{"-exitval"} < 2) ? \*STDOUT : \*STDERR |
427 | unless (defined $opts{"-output"}); |
428 | ## Default the input file |
429 | $opts{"-input"} = $0 unless (defined $opts{"-input"}); |
430 | |
431 | ## Look up input file in path if it doesnt exist. |
432 | unless ((ref $opts{"-input"}) || (-e $opts{"-input"})) { |
433 | my ($dirname, $basename) = ('', $opts{"-input"}); |
434 | my $pathsep = ($^O =~ /^(?:dos|os2|MSWin32)$/) ? ";" |
435 | : (($^O eq 'MacOS') ? ',' : ":"); |
436 | my $pathspec = $opts{"-pathlist"} || $ENV{PATH} || $ENV{PERL5LIB}; |
437 | |
438 | my @paths = (ref $pathspec) ? @$pathspec : split($pathsep, $pathspec); |
439 | for $dirname (@paths) { |
440 | $_ = File::Spec->catfile($dirname, $basename) if length; |
441 | last if (-e $_) && ($opts{"-input"} = $_); |
442 | } |
443 | } |
444 | |
445 | ## Now create a pod reader and constrain it to the desired sections. |
446 | my $parser = new Pod::Usage(USAGE_OPTIONS => \%opts); |
447 | if ($opts{"-verbose"} == 0) { |
448 | $parser->select("SYNOPSIS"); |
449 | } |
450 | elsif ($opts{"-verbose"} == 1) { |
451 | my $opt_re = '(?i)' . |
452 | '(?:OPTIONS|ARGUMENTS)' . |
453 | '(?:\s*(?:AND|\/)\s*(?:OPTIONS|ARGUMENTS))?'; |
454 | $parser->select( 'SYNOPSIS', $opt_re, "DESCRIPTION/$opt_re" ); |
455 | } |
456 | |
457 | ## Now translate the pod document and then exit with the desired status |
458 | $parser->parse_from_file($opts{"-input"}, $opts{"-output"}); |
459 | exit($opts{"-exitval"}); |
460 | } |
461 | |
462 | ##--------------------------------------------------------------------------- |
463 | |
464 | ##------------------------------- |
465 | ## Method definitions begin here |
466 | ##------------------------------- |
467 | |
468 | sub new { |
469 | my $this = shift; |
470 | my $class = ref($this) || $this; |
471 | my %params = @_; |
472 | my $self = {%params}; |
473 | bless $self, $class; |
474 | $self->initialize(); |
475 | return $self; |
476 | } |
477 | |
478 | sub begin_pod { |
479 | my $self = shift; |
480 | $self->SUPER::begin_pod(); ## Have to call superclass |
481 | my $msg = $self->{USAGE_OPTIONS}->{-message} or return 1; |
482 | my $out_fh = $self->output_handle(); |
483 | print $out_fh "$msg\n"; |
484 | } |
485 | |
486 | sub preprocess_paragraph { |
487 | my $self = shift; |
488 | local $_ = shift; |
489 | my $line = shift; |
490 | ## See if this is a heading and we arent printing the entire manpage. |
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491 | if (($self->{USAGE_OPTIONS}->{-verbose} < 2) && /^=head/) { |
360aca43 |
492 | ## Change the title of the SYNOPSIS section to USAGE |
e9fdc7d2 |
493 | s/^=head1\s+SYNOPSIS\s*$/=head1 USAGE/; |
360aca43 |
494 | ## Try to do some lowercasing instead of all-caps in headings |
495 | s{([A-Z])([A-Z]+)}{((length($2) > 2) ? $1 : lc($1)) . lc($2)}ge; |
496 | ## Use a colon to end all headings |
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497 | s/\s*$/:/ unless (/:\s*$/); |
360aca43 |
498 | $_ .= "\n"; |
499 | } |
500 | return $self->SUPER::preprocess_paragraph($_); |
501 | } |
502 | |