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Article #3289

Re: strange replace-regexp behavior

#3289
From: Lemming Productions Present...
Date: Mon, 28 Dec 1992 17:28
35 lines
2520 bytes
>>>>> On Mon, 28 Dec 1992 13:39:23 GMT, pat@gsfc.nasa.gov (patrick m. ryan)
>>>>> said:

Patrick> 	I was trying to remove a leading column of '>' characters
Patrick> from some text and got some strange behavior from replace-regexp.
Patrick> I have text something like this:

>In article 999, joe@blow said:
>>blah blah blah
>> blah blah blah

Patrick> I wanted to remove the first '>' in each line.  Thus, I did:

Patrick> 	(replace-regexp "^>" "")

Patrick> Instead of removing just the first '>' in each line, it removed
Patrick> the whole sequence of '>' characters.  It acted as though I
Patrick> has used "^>*" for the first argument.  I ended up with:

Ok, here's the deal. What emacs does is to do a re-search-forward for your
search string, deletes it, and inserts the replacement string. There goes
the "^>". Now, it repeats the re-search-forward. Lo and behold, point is
sitting just to the left of the search string "^>". It gleefully replaces
it with the replacement string, and repeats itself.

You may want to use querey-replace-regexp instead. Or do two replace-regexp
commands, the first change "^>" into something else, like "><", then do a
second replace-regexp on the new string.

--Rat                               PGP Public Key Block available upon request
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Northeastern's Stainless Steel Rat          ratinox@meceng.coe.northeastern.edu
Love is a snowmobile racing across the tundra and then suddenly it flips over,
pinning you underneath. At night, the ice weasels come.
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From: ratinox@meceng.coe.northeastern.edu (Lemming Productions Present...)
Newsgroups: comp.emacs,gnu.emacs.help,gnu.epoch.misc
Subject: Re: strange replace-regexp behavior
Message-ID: <RATINOX.92Dec28122732@splinter.coe.northeastern.edu>
Date: 28 Dec 92 17:28:34 GMT
References: <1992Dec28.133923.27974@nsisrv.gsfc.nasa.gov>
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