Getopt::Std(3)

NAME
     getopt - Process single-character switches with switch clustering

     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() functions 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, or 1 if no argument.
     Switches which take an argument don't care whether there is a space
     between the switch and the argument.

     For those of you who don't like additional 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.