#run script.pl as child process
my $script = '/myroot/public_html/cgi-bin/script.pl';
if ($pid = fork)
elsif (defined $pid)
die "Major error: $!";
Using system creates another process, exec is more appropriate here.
If you are running on Windows you should be aware that fork creates a new thread, not a new process (fork is UNIX architecture). Also (on Windows) to run a script you should prefix the script name with 'perl', since file extension association is done at application, not OS, level. See also Win32::Process and Win32::FetchCommand.