Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!seismo!rutgers!ucla-cs!sdcrdcf!burdvax!wrp
From: wrp@burdvax.PRC.Unisys.COM (William R. Pringle)
Newsgroups: comp.unix.questions
Subject: Re: awk or sed question
Message-ID: <3892@burdvax.PRC.Unisys.COM>
Date: Fri, 3-Jul-87 10:16:45 EDT
Article-I.D.: burdvax.3892
Posted: Fri Jul  3 10:16:45 1987
Date-Received: Sat, 4-Jul-87 17:23:46 EDT
References: <4780@columbia.UUCP>
Sender: news@burdvax.PRC.Unisys.COM
Distribution: world
Organization: Unisys/Paoli Research Center, Paoli, PA
Lines: 61

in article <4780@columbia.UUCP>, agw@broadway.columbia.edu (Art Werschulz) says:
> 
> 
> Hi all.
> 
> I have a file consisting of some lines that have 80 chars or fewer,
> and some with more than 80 characters (in fact, some may have more
> than 160 characters).  I wish to break up only the >80-char lines, so
> that no line has more than 80 chars.  
> 
> Here's the catch:  I want to break the long lines only at whitespace.
> Thus, I can't use 
> 
> 	% fold -80 foo.tex
> 
> since a space in the middle of a word would be disatrous.
> 
> Any suggestions?
> 
> 	Art Werschulz
> 
>  	ARPAnet:  agw@columbia.edu
> 	USEnet:   ... seismo!columbia!agw
> 	BITnet:   agw%columbia.edu@wiscvm
> 	CCNET:    agw@columbia
> 	ATTnet:   Columbia University (212) 280-3610 280-2736
> 		  Fordham University  (212) 841-5323 841-5396
=====================

Here is a little script that I use to do that. Hope it helps.

---------------- Cut Here ---------
#!/bin/sh
#
# fold lines at whitespace
#
# by Bill Pringle
#	burdvax!wrp
#

sed -e 's/	/        /g' $* |		# convert tabs to 8 spaces
awk - '
BEGIN { N = 80 }
{   if ((n = length($0)) <= N)
        print
    else {
        LEN = N
        for (i = 1; n > N; n -= LEN) {
           while (substr($0,LEN+i-1,1) != " ") {
               LEN -= 1
           }
           if (i==1) {
		printf "%s\\\n", substr($0, i, LEN)
	   } else {
		printf ">     %s\\\n", substr($0, i, LEN)
	   }
           i += LEN;
        }
        printf ">     %s\\\n", substr($0,i)
     }
} '