The 'time' command (in /usr/bin, but tcsh has its own internal one), will show you how the perl script is doing system-wise. I use tcsh and have: set time=( 5 ge: %P%X+%Dk %I+%Oio %Fpf+%Ww' ) in my .tcshrc. e.g.: 'time ls':

User mode: 0.000 Kernel mode: 0.005 Time: 0:00.00 CPU Percentage: 0.0%
0+0k 0+0io 0pf+0w
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Fun for the whole family. (The 5 in the set line makes processes that take over 5s of time always print out time statistics. Always works on make bzImage.)