Re: fgrep execution time

[Andreas Schwab]

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
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