1 /*-
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Kevin Ruddy.
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. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37 #ifndef lint
38 char copyright[] =
39 "@(#) Copyright (c) 1990 The Regents of the University of California.\n\
40 All rights reserved.\n";
41 #endif /* not lint */
42
43 #ifndef lint
44 static char sccsid[] = "@(#)fold.c 5.5 (Berkeley) 6/1/90";
45 #endif /* not lint */
46
47 #include <stdio.h>
48 #include <string.h>
49
50 #define DEFLINEWIDTH 80
51
main(argc,argv)52 main(argc, argv)
53 int argc;
54 char **argv;
55 {
56 extern int errno, optind;
57 extern char *optarg;
58 register int ch;
59 int width;
60 char *p;
61
62 width = -1;
63 while ((ch = getopt(argc, argv, "0123456789w:")) != EOF)
64 switch (ch) {
65 case 'w':
66 if ((width = atoi(optarg)) <= 0) {
67 (void)fprintf(stderr,
68 "fold: illegal width value.\n");
69 exit(1);
70 }
71 break;
72 case '0': case '1': case '2': case '3': case '4':
73 case '5': case '6': case '7': case '8': case '9':
74 if (width == -1) {
75 p = argv[optind - 1];
76 if (p[0] == '-' && p[1] == ch && !p[2])
77 width = atoi(++p);
78 else
79 width = atoi(argv[optind] + 1);
80 }
81 break;
82 default:
83 (void)fprintf(stderr,
84 "usage: fold [-w width] [file ...]\n");
85 exit(1);
86 }
87 argv += optind;
88 argc -= optind;
89
90 if (width == -1)
91 width = DEFLINEWIDTH;
92 if (!*argv)
93 fold(width);
94 else for (; *argv; ++argv)
95 if (!freopen(*argv, "r", stdin)) {
96 (void)fprintf(stderr,
97 "fold: %s: %s\n", *argv, strerror(errno));
98 exit(1);
99 } else
100 fold(width);
101 exit(0);
102 }
103
fold(width)104 fold(width)
105 register int width;
106 {
107 register int ch, col, new;
108
109 for (col = 0;;) {
110 switch (ch = getchar()) {
111 case EOF:
112 return;
113 case '\b':
114 new = col ? col - 1 : 0;
115 break;
116 case '\n':
117 case '\r':
118 new = 0;
119 break;
120 case '\t':
121 new = (col + 8) & ~7;
122 break;
123 default:
124 new = col + 1;
125 break;
126 }
127
128 if (new > width) {
129 putchar('\n');
130 col = 0;
131 }
132 putchar(ch);
133
134 switch (ch) {
135 case '\b':
136 if (col > 0)
137 --col;
138 break;
139 case '\n':
140 case '\r':
141 col = 0;
142 break;
143 case '\t':
144 col += 8;
145 col &= ~7;
146 break;
147 default:
148 ++col;
149 break;
150 }
151 }
152 }
153