1/*	$NetBSD: foldit.c,v 1.6 2003/08/07 11:17:09 agc Exp $	*/
2
3/*-
4 * Copyright (c) 1990, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#ifndef lint
34#if 0
35static char sccsid[] = "@(#)foldit.c	8.1 (Berkeley) 6/6/93";
36#endif
37__RCSID("$NetBSD: foldit.c,v 1.6 2003/08/07 11:17:09 agc Exp $");
38#endif /* not lint */
39
40#include <stdio.h>
41#include <vis.h>
42#include "extern.h"
43
44int
45foldit(const char *chunk, int col, int max, int flags)
46{
47	const char *cp;
48
49	/*
50	 * Keep track of column position. Insert hidden newline
51	 * 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