Getopt::Std(3)

NNAAMMEE
       getopt - Process single-character switches with switch
       clustering

       getopts - Process single-character switches with switch
       clustering

SSYYNNOOPPSSIISS
           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

DDEESSCCRRIIPPTTIIOONN
       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.