NAME

       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 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.