119914Swollman/*	$NetBSD: foldit.c,v 1.7 2009/02/10 23:06:31 christos Exp $	*/
250476Speter
31558Srgrimes/*-
4156905Sru * Copyright (c) 1990, 1993
5156905Sru *	The Regents of the University of California.  All rights reserved.
61558Srgrimes *
725451Speter * Redistribution and use in source and binary forms, with or without
8138593Ssam * modification, are permitted provided that the following conditions
925451Speter * are met:
10138593Ssam * 1. Redistributions of source code must retain the above copyright
11138593Ssam *    notice, this list of conditions and the following disclaimer.
12138593Ssam * 2. Redistributions in binary form must reproduce the above copyright
13138593Ssam *    notice, this list of conditions and the following disclaimer in the
14138593Ssam *    documentation and/or other materials provided with the distribution.
15138593Ssam * 3. Neither the name of the University nor the names of its contributors
16138593Ssam *    may be used to endorse or promote products derived from this software
17138593Ssam *    without specific prior written permission.
18138593Ssam *
19138593Ssam * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20138593Ssam * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
2144764Swpaul * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22138593Ssam * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23138593Ssam * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24138593Ssam * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25138593Ssam * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26181224Sthompsa * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27193664Shrs * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
2877217Sphk * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29178354Ssam * SUCH DAMAGE.
30178354Ssam */
31178354Ssam
32178354Ssam#include <sys/cdefs.h>
33142215Sglebius#ifndef lint
34159781Smlaier#if 0
35142215Sglebiusstatic char sccsid[] = "@(#)foldit.c	8.1 (Berkeley) 6/6/93";
36142215Sglebius#endif
37146987Sthompsa__RCSID("$NetBSD: foldit.c,v 1.7 2009/02/10 23:06:31 christos Exp $");
38168793Sthompsa#endif /* not lint */
39146987Sthompsa
40156905Sru#include <stdio.h>
41138593Ssam#include <vis.h>
42178354Ssam#include "extern.h"
43178354Ssam
4480057Sobrienint
4580057Sobrienfoldit(const char *chunk, int col, int max, int flags)
46138593Ssam{
47138593Ssam	const char *cp;
48144130Sbrooks
49126178Sjohan	/*
501558Srgrimes	 * Keep track of column position. Insert hidden newline
511558Srgrimes	 * if this chunk puts us over the limit.
52	 */
53again:
54	cp = chunk;
55	while (*cp) {
56		switch(*cp) {
57		case '\n':
58		case '\r':
59			col = 0;
60			break;
61		case '\t':
62			col = (col + 8) &~ 07;
63			break;
64		case '\b':
65			col = col ? col - 1 : 0;
66			break;
67		default:
68			col++;
69		}
70		if (col > (max - 2)) {
71			printf(flags & VIS_MIMESTYLE ? "=\n" : "\\\n");
72			col = 0;
73			goto again;
74		}
75		cp++;
76	}
77	return (col);
78}
79