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

# simple_shell
# This script is just an example of a very simple "shell" program.
# Cameron Hayne (macdev@hayne.net)  December 2005

my $version = 0.01;

# Functions
#--------------------------------
sub print_help()
{
    print <<EOT

This "Simple Shell" program is intended for interactive use in a
manner similar to that of the standard UNIX shells.
The only commands it understands are:
help              prints out the info you are currently reading
exit              exits from the shell
ls                lists the contents of the current folder
EOT
}

sub print_prompt()
{
    print "ss> ";
}


MAIN
{
    print "Welcome to ss (Simple Shell) version $version\n",
          "Type: help for help\n";
    print_prompt();

    while (<>)
    {
        chomp;
        my $cmd = $_;

        if ($cmd =~ /^\s*help\s*$/)
        {
            print_help();
        }
        elsif ($cmd =~ /^\s*exit\s*$/)
        {
            exit;
        }
        elsif ($cmd =~ /^\s*ls\s*$/)
        {
            system("ls");
        }
        elsif ($cmd =~ /^\s*easter egg\s*$/)
        {
            system("open http://www.bigthings.ca/alberta/pictures/egg1.jpg");
        }
        else
        {
            print "Command not recognized\n";
        }

        print_prompt();
    }
}