Path: utzoo!attcan!uunet!tank!ncar!ames!mailrus!purdue!decwrl!hplabs!hp-sdd!allyn
From: allyn@hp-sdd.hp.com (Allyn Fratkin)
Newsgroups: comp.unix.questions
Subject: Re: sed script to combine blank lines?
Message-ID: <1577@hp-sdd.HP.COM>
Date: 16 Oct 88 22:37:20 GMT
References: <192@vlsi.ll.mit.edu>
Sender: netnews@hp-sdd.HP.COM
Distribution: comp
Lines: 22

you sed experts are going way overboard here.  this is a really
trivial problem for sed.  try something simple, like the following:

sed 's/^[<sp><tab><ff>]*//; /^$/N; /^\n[<sp><tab><ff>]*$/D'

this starts by reducing a "blank" line to an empty one.  an empty
line is joined to the next line, and then if this next line is also
"blank", the first line is deleted.

i admit that this does require non-printable chars.  too bad sed
doesn't understand octal escape sequences.

to get around the non-printable chars, you could always do something
like this:

chars=`echo '\040\011\014\c'`	# use -n with bsd echo
sed "s/^[$chars]*//; /^$/N; /^\n[$chars]*$/D"

-- 
 From the virtual mind of Allyn Fratkin            allyn@sdd.hp.com
                          San Diego Division       - or -
                          Hewlett-Packard Company  uunet!ucsd!hp-sdd!allyn