There is no 'timeout' on a system command. If it hangs forever, Perl will wait forever. Are you sure collect_stats is completing OK? Perhaps you could open it with a pipe for stdout, and use a while loop to print out the lines as you get them. If you try using the while loop, use $|++ to disable buffering.

If you post an example of working code, that exhibits your problem, then you may get a more useful reply

Cheers,
R.