#!/usr/bin/perl

# if your prgram has the string "grep" in the name or in the path
# this program won't work.

open PROS, "ps -ax|grep your_program|";


while ($line = <PROS>){
	unless ($line =~ m/grep/){
		#print "it is running\n";
		exit;
	}
}

#print "it isn't running\n";
exec 'nohup /home/you/your_program &';