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From: louk@tslwat.UUCP (Lou Kates)
Newsgroups: comp.unix.shell
Subject: Re: deleting some empty lines with sed
Message-ID: <354@tslwat.UUCP>
Date: 29 Apr 91 03:47:15 GMT
References: <1991Apr27.143519.26256@daimi.aau.dk>
Reply-To: louk@tslwat.UUCP (Lou Kates)
Organization: Teleride Sage, Ltd., Waterloo
Lines: 15

In article <1991Apr27.143519.26256@daimi.aau.dk> datpete@daimi.aau.dk (Peter Andersen) writes:
>If two or more blank lines appear, I want to remove all but
>one of these.

The following  awk script (its called  nawk on my system) will do
this:

		nawk 'NF || !b; {b = !NF}'

b is a  flag which is true  if the previous input line was blank.
The first statement of  the script  prints the current line if it
has fields or  if b is false (or null as it will be on the  first
line of input). The second statement of the script sets b.

Lou Kates, Teleride Sage Ltd., louk%tslwat@watmath.waterloo.edu