Quote

ESC[1mNAMEESC[0m
Getopt::Long - Extended processing of command line options

ESC[1mSYNOPSISESC[0m
use Getopt::Long;
my $data = "file.dat";
my $length = 24;
my $verbose;
$result = GetOptions ("length=i" => \$length, # numeric
"file=s" => \$data, # string
"verbose" => \$verbose); # flag

ESC[1mDESCRIPTIONESC[0m
The Getopt::Long module implements an extended getopt function called
ESC[4mGetOptions()ESC[24m. This function adheres to the POSIX syntax for command
line options, with GNU extensions. In general, this means that options
have long names instead of single letters, and are introduced with a
double dash "--". Support for bundling of command line options, as was
the case with the more traditional single-letter approach, is provided
but not enabled by default.