#!/usr/athena/bin/perl -T
        use strict;
        use warnings;

        use CGI qw( :standard );

        # Make path safe
        $ENV{'PATH'} = '/bin:/usr/bin:/usr/athena/bin/';

        print header(),
              start_html('A Simple Example'),
              h1('A Simple Example'),
              start_form(),
              "Finger whom? ",
              textfield('user'),
              submit(),
              end_form(),
              hr();

        # Get user input
        my $user = param('user');

        if ($user) {
            # Untaint user input
            if ($user =~ /^(\w*)$/) {
                $user = $1;
                # Command is now safe
                my $output = `finger $user`;
                print pre("$output\n"),
                      hr();
            } else {
	        # User input is unsafe
                print p("Invalid username.  Please try again.");
            }
        }
        print end_html();