From: Dave Horsfall <dave@horsfall.org>
To: The Eunuchs Hysterical Society <tuhs@tuhs.org>
Subject: Re: [TUHS] Regular Expressions
Date: Mon, 10 Aug 2020 09:44:11 +1000 (EST) [thread overview]
Message-ID: <alpine.BSF.2.21.9999.2008100938290.3620@aneurin.horsfall.org> (raw)
In-Reply-To: <202008012112.071LCsdo037245@tahoe.cs.Dartmouth.EDU>
On Sat, 1 Aug 2020, Doug McIlroy wrote:
> This lesson came home with a vengeance when Al Aho wrote egrep, which
> implemented full regular expressions as DFA's. I happened to be writing
> calendar(1) at the same time, and used egrep to search calendar files
> for dates in rather free formats for today and all days through the next
> working day. [...]
I heard somewhere (a Usenix paper?) that "egrep" turned out to be faster
than "fgrep" (designed to look for fixed strings only), thus "egrep" is
now symlinked everywhere.
On my FreeBSD box (in /usr/bin):
aneurin% ls -li *grep
25471 -r-xr-xr-x 7 root wheel 40744 Oct 15 2017 bsdgrep
25480 -r-xr-xr-x 9 root wheel 82136 Oct 15 2017 bzegrep
25480 -r-xr-xr-x 9 root wheel 82136 Oct 15 2017 bzfgrep
25480 -r-xr-xr-x 9 root wheel 82136 Oct 15 2017 bzgrep
25480 -r-xr-xr-x 9 root wheel 82136 Oct 15 2017 egrep
25480 -r-xr-xr-x 9 root wheel 82136 Oct 15 2017 fgrep
25480 -r-xr-xr-x 9 root wheel 82136 Oct 15 2017 grep
25471 -r-xr-xr-x 7 root wheel 40744 Oct 15 2017 lzegrep
25471 -r-xr-xr-x 7 root wheel 40744 Oct 15 2017 lzfgrep
25471 -r-xr-xr-x 7 root wheel 40744 Oct 15 2017 lzgrep
23554 lrwxr-xr-x 1 root wheel 10 Feb 18 2011 pgrep -> /bin/pgrep
25471 -r-xr-xr-x 7 root wheel 40744 Oct 15 2017 xzegrep
25471 -r-xr-xr-x 7 root wheel 40744 Oct 15 2017 xzfgrep
25471 -r-xr-xr-x 7 root wheel 40744 Oct 15 2017 xzgrep
25480 -r-xr-xr-x 9 root wheel 82136 Oct 15 2017 zegrep
25480 -r-xr-xr-x 9 root wheel 82136 Oct 15 2017 zfgrep
25480 -r-xr-xr-x 9 root wheel 82136 Oct 15 2017 zgrep
OK, there's a few strays in there...
-- Dave
next prev parent reply other threads:[~2020-08-09 23:45 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-01 21:12 Doug McIlroy
2020-08-09 23:44 ` Dave Horsfall [this message]
2020-08-10 0:50 ` Rob Pike
-- strict thread matches above, loose matches on Subject: below --
2020-08-02 4:59 Rudi Blom
2020-08-01 0:00 Noel Chiappa
2020-07-31 22:57 Will Senn
2020-08-01 0:01 ` Bakul Shah
2020-08-01 0:36 ` Rob Pike
2020-08-01 0:53 ` John P. Linderman
2020-08-01 1:31 ` Bakul Shah
2020-08-01 1:39 ` Larry McVoy
2020-08-01 2:33 ` Will Senn
2020-08-01 2:50 ` Rich Morin
2020-08-01 3:01 ` Larry McVoy
2020-08-01 3:07 ` Will Senn
2020-08-01 4:31 ` Earl Baugh
2020-08-01 4:53 ` ron minnich
2020-08-01 5:48 ` Andrew Hume
2020-08-01 13:31 ` Richard Salz
2020-08-01 13:43 ` Andrew Hume
2020-08-02 0:45 ` Christopher Browne
2020-08-09 1:00 ` Dave Horsfall
2020-08-09 1:15 ` Nelson H. F. Beebe
2020-08-09 23:53 ` Dave Horsfall
2020-08-10 1:38 ` John Cowan
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