will time a single run of a command - but the results can vary from run
script runs a command the number of times you specify,
then averages the results.
runtime -5 getdata 0.5 outfile
...wait a while...
runtime summary - 5 runs of
% getdata 0.5 outfile
(working directory = /users/jerry/.src/getdata)
First run started at: Thu Mar 19 09:33:58 EST 1992
Last run finished at: Thu Mar 19 09:36:41 EST 1992
RUN # ***INDIVIDUAL RESULTS***
1 1.0u 7.4s 1:06 12% 0+108k 0+0io 0pf+0w
2 0.2u 0.8s 0:05 16% 0+128k 0+0io 0pf+0w
3 0.2u 1.3s 0:11 13% 0+116k 0+0io 0pf+0w
4 0.4u 2.7s 0:25 12% 0+108k 0+0io 0pf+0w
5 0.9u 5.9s 0:53 12% 0+108k 0+0io 0pf+0w
0.54u 3.62s 0:32 0+113k 0+0io 0pf+0w
It's good for testing different versions of a program to find the
fastest (or slowest!).
If you're writing a program that will run a lot, shaving 10% or 20% off
its time can be worth the work.
Note that the command you run can't have any redirection in it; that's
does some redirection of its own.
You can redirect the output of runtime into a log file though, and run
the whole mess in the background. For example:
runtime -5 getdata 0.5 outfile > runtime.out &
The summary will go to the runtime.out