1 /*-
2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. 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. 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 * @(#) Copyright (c) 1990, 1993 The Regents of the University of California. All rights reserved.
33 * @(#)fold.c 8.1 (Berkeley) 6/6/93
34 * $FreeBSD: head/usr.bin/fold/fold.c 227165 2011-11-06 08:15:23Z ed $
35 */
36
37 #include <err.h>
38 #include <limits.h>
39 #include <locale.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <unistd.h>
44 #include <wchar.h>
45 #include <wctype.h>
46
47 #define DEFLINEWIDTH 80
48
49 void fold(int);
50 static int newpos(int, wint_t);
51 static void usage(void);
52
53 static int bflag; /* Count bytes, not columns */
54 static int sflag; /* Split on word boundaries */
55
56 int
main(int argc,char ** argv)57 main(int argc, char **argv)
58 {
59 int ch, previous_ch;
60 int rval, width;
61
62 (void) setlocale(LC_CTYPE, "");
63
64 width = -1;
65 previous_ch = 0;
66 while ((ch = getopt(argc, argv, "0123456789bsw:")) != -1) {
67 switch (ch) {
68 case 'b':
69 bflag = 1;
70 break;
71 case 's':
72 sflag = 1;
73 break;
74 case 'w':
75 if ((width = atoi(optarg)) <= 0) {
76 errx(1, "illegal width value");
77 }
78 break;
79 case '0': case '1': case '2': case '3': case '4':
80 case '5': case '6': case '7': case '8': case '9':
81 /* Accept a width as eg. -30. Note that a width
82 * specified using the -w option is always used prior
83 * to this undocumented option. */
84 switch (previous_ch) {
85 case '0': case '1': case '2': case '3': case '4':
86 case '5': case '6': case '7': case '8': case '9':
87 /* The width is a number with multiple digits:
88 * add the last one. */
89 width = width * 10 + (ch - '0');
90 break;
91 default:
92 /* Set the width, unless it was previously
93 * set. For instance, the following options
94 * would all give a width of 5 and not 10:
95 * -10 -w5
96 * -5b10
97 * -5 -10b */
98 if (width == -1)
99 width = ch - '0';
100 break;
101 }
102 break;
103 default:
104 usage();
105 }
106 previous_ch = ch;
107 }
108 argv += optind;
109 argc -= optind;
110
111 if (width == -1)
112 width = DEFLINEWIDTH;
113 rval = 0;
114 if (!*argv)
115 fold(width);
116 else for (; *argv; ++argv)
117 if (!freopen(*argv, "r", stdin)) {
118 warn("%s", *argv);
119 rval = 1;
120 } else
121 fold(width);
122 exit(rval);
123 }
124
125 static void
usage(void)126 usage(void)
127 {
128 (void)fprintf(stderr, "usage: fold [-bs] [-w width] [file ...]\n");
129 exit(1);
130 }
131
132 /*
133 * Fold the contents of standard input to fit within WIDTH columns (or bytes)
134 * and write to standard output.
135 *
136 * If sflag is set, split the line at the last space character on the line.
137 * This flag necessitates storing the line in a buffer until the current
138 * column > width, or a newline or EOF is read.
139 *
140 * The buffer can grow larger than WIDTH due to backspaces and carriage
141 * returns embedded in the input stream.
142 */
143 void
fold(int width)144 fold(int width)
145 {
146 static wchar_t *buf;
147 static int buf_max;
148 int col, i, indx, space;
149 wint_t ch;
150
151 col = indx = 0;
152 while ((ch = getwchar()) != WEOF) {
153 if (ch == '\n') {
154 wprintf(L"%.*ls\n", indx, buf);
155 col = indx = 0;
156 continue;
157 }
158 if ((col = newpos(col, ch)) > width) {
159 if (sflag) {
160 i = indx;
161 while (--i >= 0 && !iswblank(buf[i]))
162 ;
163 space = i;
164 }
165 if (sflag && space != -1) {
166 space++;
167 wprintf(L"%.*ls\n", space, buf);
168 wmemmove(buf, buf + space, indx - space);
169 indx -= space;
170 col = 0;
171 for (i = 0; i < indx; i++)
172 col = newpos(col, buf[i]);
173 } else {
174 wprintf(L"%.*ls\n", indx, buf);
175 col = indx = 0;
176 }
177 col = newpos(col, ch);
178 }
179 if (indx + 1 > buf_max) {
180 buf_max += LINE_MAX;
181 buf = realloc(buf, sizeof(*buf) * buf_max);
182 if (buf == NULL)
183 err(1, "realloc()");
184 }
185 buf[indx++] = ch;
186 }
187
188 if (indx != 0)
189 wprintf(L"%.*ls", indx, buf);
190 }
191
192 /*
193 * Update the current column position for a character.
194 */
195 static int
newpos(int col,wint_t ch)196 newpos(int col, wint_t ch)
197 {
198 char buf[MB_LEN_MAX];
199 size_t len;
200 int w;
201
202 if (bflag) {
203 len = wcrtomb(buf, ch, NULL);
204 col += len;
205 } else
206 switch (ch) {
207 case '\b':
208 if (col > 0)
209 --col;
210 break;
211 case '\r':
212 col = 0;
213 break;
214 case '\t':
215 col = (col + 8) & ~7;
216 break;
217 default:
218 if ((w = wcwidth(ch)) > 0)
219 col += w;
220 break;
221 }
222
223 return (col);
224 }
225