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Path: utzoo!linus!philabs!cmcl2!seismo!ut-sally!jsq
From: jsq@ut-sally.UUCP (John Quarterman)
Newsgroups: net.unix-wizards
Subject: Re: nroff - help wanted
Message-ID: <2450@ut-sally.UUCP>
Date: Sun, 1-Jul-84 23:11:20 EDT
Article-I.D.: ut-sally.2450
Posted: Sun Jul  1 23:11:20 1984
Date-Received: Tue, 3-Jul-84 03:40:36 EDT
References: <407@kvvax4.UUCP> <400005@bradley.UUCP> <125@hwcs.UUCP>
Organization: U. Texas CS Dept., Austin, Texas
Lines: 28

Not terribly fast, but easy to do and requires no nroff changes:

#!/bin/awk -f
# A filter, ff, to insert form feeds at page boundaries in nroff output
# and possibly to shorten the pages at the same time.
BEGIN {
	nroffpage = 66;		# the usual default nroff page length
	printpage = 63; 	# the shortest printer page I've run across
	if (printpage > nroffpage) {
		trimtop = 0;
		trimend = nroffpage;
	} else {
		totrim = nroffpage - printpage;
		trimtop = sprintf ("%d", totrim / 2 + .5);
		trimend = nroffpage - (totrim - trimtop);
	}
	count = 0;
}
{
	if (++count == nroffpage) {
		count = 0;
		printf ("");	# a form feed, ASCII 014 or 0x0C, control L
	} else if (count > trimtop && count < trimend)
		print $0;
}
-- 
John Quarterman, CS Dept., University of Texas, Austin, Texas 78712 USA
jsq@ut-sally.ARPA, jsq@ut-sally.UUCP, {ihnp4,seismo,ctvax}!ut-sally!jsq