nroff - help wanted

[John Quarterman]

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 at ut-sally.ARPA, jsq at ut-sally.UUCP, {ihnp4,seismo,ctvax}!ut-sally!jsq