docs/cut
view code/cut.c__openbsd.2008-06-27 @ 38:ec76f8926598
clarify a statement
Thanks to Francesc for the suggestion.
| author | markus schnalke <meillo@marmaro.de> |
|---|---|
| date | Tue, 06 Oct 2015 10:43:26 +0200 |
| parents | |
| children |
line source
1 /* $OpenBSD: cut.c,v 1.13 2008/06/27 08:02:13 sobrado Exp $ */
2 /* $NetBSD: cut.c,v 1.9 1995/09/02 05:59:23 jtc Exp $ */
4 /*
5 * Copyright (c) 1989, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * Adam S. Moskowitz of Menlo Consulting and Marciano Pitargue.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
36 #ifndef lint
37 static char copyright[] =
38 "@(#) Copyright (c) 1989, 1993\n\
39 The Regents of the University of California. All rights reserved.\n";
40 #endif /* not lint */
42 #ifndef lint
43 #if 0
44 static char sccsid[] = "@(#)cut.c 8.3 (Berkeley) 5/4/95";
45 #endif
46 static char rcsid[] = "$OpenBSD: cut.c,v 1.13 2008/06/27 08:02:13 sobrado Exp $";
47 #endif /* not lint */
49 #include <ctype.h>
50 #include <err.h>
51 #include <errno.h>
52 #include <limits.h>
53 #include <locale.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <unistd.h>
59 int cflag;
60 char dchar;
61 int dflag;
62 int fflag;
63 int sflag;
65 void c_cut(FILE *, char *);
66 void f_cut(FILE *, char *);
67 void get_list(char *);
68 void usage(void);
70 int
71 main(int argc, char *argv[])
72 {
73 FILE *fp;
74 void (*fcn)(FILE *, char *);
75 int ch;
77 setlocale (LC_ALL, "");
79 dchar = '\t'; /* default delimiter is \t */
81 /* Since we don't support multi-byte characters, the -c and -b
82 options are equivalent, and the -n option is meaningless. */
83 while ((ch = getopt(argc, argv, "b:c:d:f:sn")) != -1)
84 switch(ch) {
85 case 'b':
86 case 'c':
87 fcn = c_cut;
88 get_list(optarg);
89 cflag = 1;
90 break;
91 case 'd':
92 dchar = *optarg;
93 dflag = 1;
94 break;
95 case 'f':
96 get_list(optarg);
97 fcn = f_cut;
98 fflag = 1;
99 break;
100 case 's':
101 sflag = 1;
102 break;
103 case 'n':
104 break;
105 case '?':
106 default:
107 usage();
108 }
109 argc -= optind;
110 argv += optind;
112 if (fflag) {
113 if (cflag)
114 usage();
115 } else if (!cflag || dflag || sflag)
116 usage();
118 if (*argv)
119 for (; *argv; ++argv) {
120 if (!(fp = fopen(*argv, "r")))
121 err(1, "%s", *argv);
122 fcn(fp, *argv);
123 (void)fclose(fp);
124 }
125 else
126 fcn(stdin, "stdin");
127 exit(0);
128 }
130 int autostart, autostop, maxval;
132 char positions[_POSIX2_LINE_MAX + 1];
134 void
135 get_list(char *list)
136 {
137 int setautostart, start, stop;
138 char *pos;
139 char *p;
141 /*
142 * set a byte in the positions array to indicate if a field or
143 * column is to be selected; use +1, it's 1-based, not 0-based.
144 * This parser is less restrictive than the Draft 9 POSIX spec.
145 * POSIX doesn't allow lists that aren't in increasing order or
146 * overlapping lists. We also handle "-3-5" although there's no
147 * real reason too.
148 */
149 while ((p = strsep(&list, ", \t"))) {
150 setautostart = start = stop = 0;
151 if (*p == '-') {
152 ++p;
153 setautostart = 1;
154 }
155 if (isdigit(*p)) {
156 start = stop = strtol(p, &p, 10);
157 if (setautostart && start > autostart)
158 autostart = start;
159 }
160 if (*p == '-') {
161 if (isdigit(p[1]))
162 stop = strtol(p + 1, &p, 10);
163 if (*p == '-') {
164 ++p;
165 if (!autostop || autostop > stop)
166 autostop = stop;
167 }
168 }
169 if (*p)
170 errx(1, "[-cf] list: illegal list value");
171 if (!stop || !start)
172 errx(1, "[-cf] list: values may not include zero");
173 if (stop > _POSIX2_LINE_MAX)
174 errx(1, "[-cf] list: %d too large (max %d)",
175 stop, _POSIX2_LINE_MAX);
176 if (maxval < stop)
177 maxval = stop;
178 for (pos = positions + start; start++ <= stop; *pos++ = 1)
179 ;
180 }
182 /* overlapping ranges */
183 if (autostop && maxval > autostop)
184 maxval = autostop;
186 /* set autostart */
187 if (autostart)
188 memset(positions + 1, '1', autostart);
189 }
191 /* ARGSUSED */
192 void
193 c_cut(FILE *fp, char *fname)
194 {
195 int ch, col;
196 char *pos;
198 for (;;) {
199 pos = positions + 1;
200 for (col = maxval; col; --col) {
201 if ((ch = getc(fp)) == EOF)
202 return;
203 if (ch == '\n')
204 break;
205 if (*pos++)
206 (void)putchar(ch);
207 }
208 if (ch != '\n') {
209 if (autostop)
210 while ((ch = getc(fp)) != EOF && ch != '\n')
211 (void)putchar(ch);
212 else
213 while ((ch = getc(fp)) != EOF && ch != '\n')
214 ;
215 }
216 (void)putchar('\n');
217 }
218 }
220 void
221 f_cut(FILE *fp, char *fname)
222 {
223 int ch, field, isdelim;
224 char *pos, *p, sep;
225 int output;
226 size_t len;
227 char *lbuf, *tbuf;
229 for (sep = dchar, tbuf = NULL; (lbuf = fgetln(fp, &len));) {
230 output = 0;
231 if (lbuf[len - 1] != '\n') {
232 /* no newline at the end of the last line so add one */
233 if ((tbuf = (char *)malloc(len + 1)) == NULL)
234 err(1, NULL);
235 memcpy(tbuf, lbuf, len);
236 tbuf[len] = '\n';
237 lbuf = tbuf;
238 }
239 for (isdelim = 0, p = lbuf;; ++p) {
240 ch = *p;
241 /* this should work if newline is delimiter */
242 if (ch == sep)
243 isdelim = 1;
244 if (ch == '\n') {
245 if (!isdelim && !sflag)
246 (void)fwrite(lbuf, len, 1, stdout);
247 break;
248 }
249 }
250 if (!isdelim)
251 continue;
253 pos = positions + 1;
254 for (field = maxval, p = lbuf; field; --field, ++pos) {
255 if (*pos) {
256 if (output++)
257 (void)putchar(sep);
258 while ((ch = *p++) != '\n' && ch != sep)
259 (void)putchar(ch);
260 } else
261 while ((ch = *p++) != '\n' && ch != sep)
262 ;
263 if (ch == '\n')
264 break;
265 }
266 if (ch != '\n') {
267 if (autostop) {
268 if (output)
269 (void)putchar(sep);
270 for (; (ch = *p) != '\n'; ++p)
271 (void)putchar(ch);
272 } else
273 for (; (ch = *p) != '\n'; ++p)
274 ;
275 }
276 (void)putchar('\n');
277 }
278 if (tbuf)
279 free(tbuf);
280 }
282 void
283 usage(void)
284 {
285 (void)fprintf(stderr,
286 "usage: cut -b list [-n] [file ...]\n"
287 " cut -c list [file ...]\n"
288 " cut -f list [-s] [-d delim] [file ...]\n");
289 exit(1);
290 }