Even assuming you mean int num_proc = system("cat /proc/cpuinfo | grep -c processor >> /dev/null 2>&1"); I dont see how this will give you the # of cpus. num-proc will only contain the status of the system call, not the result of the grep, wont it? ----- You're right, it's giving me the return value from grep, which is 0. I need the string printed by grep ... How can I get this??? Thanks. :b!