


Getopt::Std(3p)  Perl Programmers Reference Guide Getopt::Std(3p)


NAME
       Getopt::Std, getopt, getopts - Process single-character
       switches with switch clustering

SYNOPSIS
           use Getopt::Std;

           getopt('oDI');    # -o, -D & -I take arg.  Sets $opt_* as a side effect.
           getopt('oDI', \%opts);    # -o, -D & -I take arg.  Values in %opts
           getopts('oif:');  # -o & -i are boolean flags, -f takes an argument
                             # Sets $opt_* as a side effect.
           getopts('oif:', \%opts);  # options as above. Values in %opts

DESCRIPTION
       The getopt() function processes single-character switches
       with switch clustering.  Pass one argument which is a
       string containing all switches that take an argument.  For
       each switch found, sets $opt_x (where x is the switch
       name) to the value of the argument if an argument is
       expected, or 1 otherwise.  Switches which take an argument
       don't care whether there is a space between the switch and
       the argument.

       The getopts() function is similar, but you should pass to
       it the list of all switches to be recognized.  If
       unspecified switches are found on the command-line, the
       user will be warned that an unknown option was given.  The
       getopts() function returns true unless an invalid option
       was found.

       Note that, if your code is running under the recommended
       "use strict 'vars'" pragma, you will need to declare these
       package variables with "our":

           our($opt_x, $opt_y);

       For those of you who don't like additional global
       variables being created, getopt() and getopts() will also
       accept a hash reference as an optional second argument.
       Hash keys will be x (where x is the switch name) with key
       values the value of the argument or 1 if no argument is
       specified.

       To allow programs to process arguments that look like
       switches, but aren't, both functions will stop processing
       switches when they see the argument "--".  The "--" will
       be removed from @ARGV.

"--help" and "--version"
       If "-" is not a recognized switch letter, getopts()
       supports arguments "--help" and "--version".  If
       "main::HELP_MESSAGE()" and/or "main::VERSION_MESSAGE()"
       are defined, they are called; the arguments are the output
       file handle, the name of option-processing package, its



perl v5.10.1                2009-10-12                          1





Getopt::Std(3p)  Perl Programmers Reference Guide Getopt::Std(3p)


       version, and the switches string.  If the subroutines are
       not defined, an attempt is made to generate intelligent
       messages; for best results, define $main::VERSION.

       If embedded documentation (in pod format, see perlpod) is
       detected in the script, "--help" will also show how to
       access the documentation.

       Note that due to excessive paranoia, if
       $Getopt::Std::STANDARD_HELP_VERSION isn't true (the
       default is false), then the messages are printed on
       STDERR, and the processing continues after the messages
       are printed.  This being the opposite of the standard-
       conforming behaviour, it is strongly recommended to set
       $Getopt::Std::STANDARD_HELP_VERSION to true.

       One can change the output file handle of the messages by
       setting $Getopt::Std::OUTPUT_HELP_VERSION.  One can print
       the messages of "--help" (without the "Usage:" line) and
       "--version" by calling functions help_mess() and
       version_mess() with the switches string as an argument.




































perl v5.10.1                2009-10-12                          2


