use strict;
use warnings;

##</code><code>##

use CGI;

##</code><code>##

use CGI::Carp qw/fatalsToBrowser/;

##</code><code>##

my $err = system("who",">>/var/www/cgi-bin/new.txt");
unless ($err == 0)
{
   die "who command failed: $?";
}