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Re: fgrep execution time
From: |
Andreas Schwab |
Subject: |
Re: fgrep execution time |
Date: |
Tue, 22 Feb 2005 15:54:32 +0100 |
User-agent: |
Gnus/5.110002 (No Gnus v0.2) Emacs/22.0.50 (gnu/linux) |
David Bailey <address@hidden> writes:
> ==> Using GNU grep
>
> time yes "a very long file" | \
> head -10000 | /usr/local/bin/fgrep -f /dev/null
> 0.00u 0.01s 0:07.95 0.1%
>
> time yes "a very long file" | \
> head -100000 | /usr/local/bin/fgrep -f /dev/null
> 0.05u 0.03s 1:27.24 0.0%
>
> time yes "a very long file" | \
> head -1000000 | /usr/local/bin/fgrep -f /dev/null
> 0.27u 0.14s 14:35.35 0.0%
>
> Over 14 minutes for a 17MB file.
Looks like you are timing something unrelated. Note that the CPU time is
0.27+0.14 seconds, ie. neglectable, thus GNU grep is unlikely to blame for
the big real time.
Andreas.
--
Andreas Schwab, SuSE Labs, address@hidden
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
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"And now for something completely different."