#!/usr/bin/perl
use strict;
use warnings;
use POSIX ":sys_wait_h";

$|++;

print "Content-type:text/plain\n\nStarting script.....\n\n";

my $pid;
if (!defined($pid = fork)) {
    die "Could not fork! $!";
}
elsif ($pid) {
    # parent - clean up when child exits
    1 while (waitpid($pid,WNOHANG) != -1);
    cleanup();
    exit(0);
}
else {
    # child - does the processing
    print "Processing...\n\n";
    sleep(5);
    print "Finished...\n\n";
    exit(0);
}

sub cleanup {
    # do the clean up here
}