1 Module Getopt::Long - extended processing of command line options
2 =================================================================
4 Module Getopt::Long implements an extended getopt function called
5 GetOptions(). This function implements the POSIX standard for command
6 line options, with GNU extensions, while still capable of handling
7 the traditional one-letter options.
8 In general, this means that command line options can have long names
9 instead of single letters, and are introduced with a double dash `--'.
11 Optionally, Getopt::Long can support the traditional bundling of
12 single-letter command line options.
14 Getopt::Long::GetOptions() is part of the Perl 5 distribution. It is
15 the successor of newgetopt.pl that came with Perl 4. It is fully
16 upward compatible. In fact, the Perl 5 version of newgetopt.pl is just
17 a wrapper around the module.
19 For complete documentation, see the Getopt::Long POD document or use
29 Major advantage of using long option names is that it is much easier
30 to memorize the option names. Using single-letter names one quickly
31 runs into the problem that there is no logical relationship between
32 the semantics of the selected option and its option letter.
33 Disadvantage is that it requires more typing. Getopt::Long provides
34 for option name abbreviation, so option names may be abbreviated to
35 uniqueness. Also, modern shells like Cornell's tcsh support option
36 name completion. As a rule of thumb, you can use abbreviations freely
37 while running commands interactively but always use the full names in
42 --long --width=80 --height=24
46 -long (convenience) +width=80 (deprecated) -height 24 (traditional)
48 By default, long option names are case insensitive.
50 * Single-letter options and bundling
52 When single-letter options are requested, Getopt::Long allows the
53 option names to be bundled, e.g. "-abc" is equivalent to "-a -b -c".
54 In this case, long option names must be introduced with the POSIX "--"
59 -lgAd (bundle) -xw 80 (bundle, w takes a value) -xw80 (same)
60 even -l24w80 (l = 24 and w = 80)
62 By default, single-letter option names are case sensitive.
66 - options can have alternative names, using an alternative name
67 will behave as if the primary name was used;
68 - options can be negatable, e.g. "debug" will switch it on, while
69 "nodebug" will switch it off.
70 - options can set values, but also add values producing an array
71 of values instead of a single scalar value, or set values in a hash.
75 Using Getopt::Long gives the programmer ultimate control over the
76 command line options and how they must be handled:
78 - by setting a global variable in the calling program;
79 - by setting a specified variable;
80 - by entering the option name and the value in an associative array
81 (hash) or object (if it is a blessed hash);
82 - by calling a user-specified subroutine with the option name and
83 the value as arguments;
84 - combinations of the above.
88 The module contains a special method, Getopt::Long::Configure, to
89 control configuration variables to activate (or de-activate) specific
90 behavior. It can be called with one or more names of options:
94 Restore default settings.
98 Allow option names to be abbreviated to uniqueness.
102 Allow '+' to start options.
106 Compatibility with GNU getopt_long().
111 Whether non-options are allowed to be mixed with options.
115 -foo arg1 -bar arg2 arg3
119 -foo -bar arg1 arg2 arg3
121 (provided -foo does not take an argument value).
123 require_order means that options processing
124 terminates when the first non-option is encountered.
126 -foo arg1 -bar arg2 arg3
130 -foo -- arg1 -bar arg2 arg3
134 Setting this variable to a non-zero value will allow
135 single-character options to be bundled. To distinguish bundles
136 from long option names, long options must be introduced with
137 "--" and single-character options (and bundles) with "-".
141 Ignore case when matching options.
145 Do not issue error messages for unknown options, but leave
146 them (pass-through) in @ARGV.
150 The string that starts options. See also prefix_pattern.
154 A Perl pattern that identifies the strings that introduce
155 options. Default is (--|-|\+) unless environment variable
156 POSIXLY_CORRECT has been set, in which case it is (--|-).
160 Enable copious debugging output.
162 * Object oriented interface:
164 Using the object oriented interface, multiple parser objects can be
165 instantiated, each having their own configuration settings:
167 $p1 = new Getopt::Long::Parser (config => ["posix"]);
168 $p2 = new Getopt::Long::Parser (config => ["no_posix"]);
169 if ($p1->getoptions(...options descriptions...)) ...
174 The official version for module Getopt::Long comes with the Perl 5
176 Newer versions will be made available on the Comprehensive Perl Archive
177 Network (CPAN), see "http://www.perl.com/CPAN/authors/Johan_Vromans".
178 Or use the CPAN search engine:
179 http://search.cpan.org/search?mode=module&query=Getopt::Long
180 http://search.cpan.org/search?module=Getopt::Long
182 COPYRIGHT AND DISCLAIMER
183 ========================
185 Module Getopt::Long is Copyright 2001,1990 by Johan Vromans.
186 This program is free software; you can redistribute it and/or
187 modify it under the terms of the Perl Artistic License or the
188 GNU General Public License as published by the Free Software
189 Foundation; either version 2 of the License, or (at your option) any
192 -------------------------------------------------------------------
193 Johan Vromans jvromans@squirrel.nl
194 Squirrel Consultancy Haarlem, the Netherlands
195 http://www.squirrel.nl http://www.squirrel.nl/people/jvromans
196 ------------------ "Arms are made for hugging" --------------------