1 /* $NetBSD: foldit.c,v 1.7 2009/02/10 23:06:31 christos 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
35 static char sccsid[] = "@(#)foldit.c 8.1 (Berkeley) 6/6/93";
36 #endif
37 __RCSID("$NetBSD: foldit.c,v 1.7 2009/02/10 23:06:31 christos Exp $");
38 #endif /* not lint */
39
40 #include <stdio.h>
41 #include <vis.h>
42 #include "extern.h"
43
44 int
foldit(const char * chunk,int col,int max,int flags)45 foldit(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 */
53 again:
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