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Date: Thu, 26 Oct 2006 00:28:41 -0700
From: Brian Dessent <brian@dessent.net>
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To: fergus <fergus@bonhard.uklinux.net>
CC: cygwin@cygwin.com
Subject: Re: Easy? sed syntax
References: <000001c6f8c7$3452f4b0$240210ac@tcgp.dundee.ac.uk>
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fergus wrote:

> In any string (eg "xaaabababbbxaabbbabx") remove all instances of "ab" and
> keep on doing this as long as you can.
> 
> Do it once:
> 
>     echo xaaabababbbxaabbbabx | sed 's/ab//g'
>     xaabbxabbx

echo xaaabababbbxaabbbabx | sed -e :a -e 's/ab//' -e ta

See section 3.7 of the sed manual.  The idiom of ":a ... ta" creates a
label 'a' and then branches back to that label (repeating the s///) as
long as there was a successful match.

Brian

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