Perl Getopt and GetOptions

Perl Getopt is a module that allows command line options to be passed to Perl scripts. It provides a way to define options and their values, as well as help messages and error handling.

GetOptions is a function within the Getopt module that parses command line options. It takes an array of option definitions, which specify the option name, the type of value it expects, and any aliases or default values.

Here is an example of using GetOptions:

use Getopt::Long;

my $verbose = 0;
my $input_file;

GetOptions(
    "verbose" => \$verbose,
    "input=s" => \$input_file,
) or die "Error in command line arguments";

print "Verbose mode enabled\n" if $verbose;
print "Input file: $input_file\n" if $input_file;

In this example, the script expects two options: --verbose, which is a boolean option that sets $verbose to true, and --input, which expects a string value that is stored in $input_file. If the user provides an invalid option or value, the script will die with an error message.