Down To Work - Perl

Now, with the hard sell out of the way, let's get down to the nitty-gritty of how Getopt::Long.pm works. Consider the following simple example:


#!/usr/bin/perl
 
# import module
use Getopt::Long;
 
# set default value for option
$debug = 0;
 
# get value of debug flag
$result = GetOptions ("debug" => $debug);  
 
# print value
print "Debug flag is $debug";



Now, try running this code as is:

$ ./script.pl
Debug flag is 0

And then try running it after adding a "--debug" command-line option:

$ ./script.pl --debug
Debug flag is 1

As you can see, the Perl code now recognizes the "--debug" flag on the command line, and sets a Boolean variable to true within the script.