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Date: 13 Aug 2010 18:51:46 -0000
Message-ID: <20100813185146.2645.qmail@joyce.lan>
From: John Levine <johnl@iecc.com>
To: freebsd-questions@freebsd.org
In-Reply-To: <201008131601.34182.j.mckeown@ru.ac.za>
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Cc: j.mckeown@ru.ac.za
Subject: Re: Grepping a list of words
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>> Since I will have a need to run this check frequently, any suggestions for
>> a better approach are welcome.
>
>sort -u and comm(1)?

sort is O(N log N) while grep is O(N)

Which is faster depends on the constant factors in each, but as the
data sets get bigger, the log N term will dominate.  That is, for
small sets of data, I don't know which will be faster, but either will
be fast enough so who cares.  For large sets of data, the sort will be
slow.

R's,
John