1 /* $OpenBSD: foldit.c,v 1.8 2020/08/17 18:41:23 martijn Exp $ */
2 /* $NetBSD: foldit.c,v 1.4 1994/12/20 16:13:02 jtc Exp $ */
3
4 /*-
5 * Copyright (c) 1990, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #include <stdio.h>
34
35 int foldit(char *chunk, int col, int max);
36
37 int
foldit(char * chunk,int col,int max)38 foldit(char *chunk, int col, int max)
39 {
40 char *cp;
41 int first = (col != 0);
42
43 /*
44 * Keep track of column position. Insert hidden newline
45 * if this chunk puts us over the limit.
46 */
47 again:
48 cp = chunk;
49 while (*cp) {
50 switch(*cp) {
51 case '\n':
52 case '\r':
53 col = 0;
54 break;
55 case '\t':
56 col = (col + 8) & ~07;
57 break;
58 case '\b':
59 col = col ? col - 1 : 0;
60 break;
61 default:
62 col++;
63 }
64 if (col > (max - 2)) {
65 if (!first)
66 return (col);
67 printf("\\\n");
68 col = 0;
69 first = 0;
70 goto again;
71 }
72 cp++;
73 }
74 return (col);
75 }
76