4.4BSD/usr/src/old/awk/test/t.roff

NF > 0	{
	for (i = 1; i <= NF; i++) {
		n = length($i)
		if (n + olen >= 60) {
			print oline
			olen = n
			oline = $i
		} else {
			oline = oline " " $i
			olen += n
		}
	}
}

NF == 0 {
	print oline
	olen = 0
}

END {
	if (olen > 0)
		print oline
}