#!/usr/bin/perl
use warnings;
use strict;

# write the 'Hello World' program with help, a version identifier and internationalization

use Getopt::Std;
my %options;
# the 'getopts' subroutine takes as arguments a specification (the letters we want to know about)
# and a hash which will store the values for the letters
getopts("vhl:",\%options);

if ($options{v}) {
    print "Hello World, version 3.\n";
    exit;
} elsif ($options{h}) {
    print <<EOF;

$0: Typical Hello World program

Syntax: $0 [-v|-h|-l <language>]

    -h : This help message
    -v : Print version on standard output and exit
    -l : Turn on international language support
EOF
    exit;
} elsif ($options{l}) {
    if ($options{l} eq "french") {
        print "Bonjour, tout le monde.\n";
    } else {
        die "$0: unsupported language\n";
    }
} else {
    print "Hello, world.\n";
}