docs/cut
view code/cut.c__freebsd.1994-05-27 @ 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 /*
2 * Copyright (c) 1989, 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 * Adam S. Moskowitz of Menlo Consulting and Marciano Pitargue.
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 */
37 #ifndef lint
38 static char copyright[] =
39 "@(#) Copyright (c) 1989, 1993\n\
40 The Regents of the University of California. All rights reserved.\n";
41 #endif /* not lint */
43 #ifndef lint
44 static char sccsid[] = "@(#)cut.c 8.1 (Berkeley) 6/6/93";
45 #endif /* not lint */
47 #include <ctype.h>
48 #include <errno.h>
49 #include <limits.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
54 int cflag;
55 char dchar;
56 int dflag;
57 int fflag;
58 int sflag;
60 void c_cut __P((FILE *, char *));
61 void err __P((const char *, ...));
62 void f_cut __P((FILE *, char *));
63 void get_list __P((char *));
64 void usage __P((void));
66 int
67 main(argc, argv)
68 int argc;
69 char *argv[];
70 {
71 FILE *fp;
72 void (*fcn) __P((FILE *, char *));
73 int ch;
75 dchar = '\t'; /* default delimiter is \t */
77 while ((ch = getopt(argc, argv, "c:d:f:s")) != EOF)
78 switch(ch) {
79 case 'c':
80 fcn = c_cut;
81 get_list(optarg);
82 cflag = 1;
83 break;
84 case 'd':
85 dchar = *optarg;
86 dflag = 1;
87 break;
88 case 'f':
89 get_list(optarg);
90 fcn = f_cut;
91 fflag = 1;
92 break;
93 case 's':
94 sflag = 1;
95 break;
96 case '?':
97 default:
98 usage();
99 }
100 argc -= optind;
101 argv += optind;
103 if (fflag) {
104 if (cflag)
105 usage();
106 } else if (!cflag || dflag || sflag)
107 usage();
109 if (*argv)
110 for (; *argv; ++argv) {
111 if (!(fp = fopen(*argv, "r")))
112 err("%s: %s\n", *argv, strerror(errno));
113 fcn(fp, *argv);
114 (void)fclose(fp);
115 }
116 else
117 fcn(stdin, "stdin");
118 exit(0);
119 }
121 int autostart, autostop, maxval;
123 char positions[_POSIX2_LINE_MAX + 1];
125 void
126 get_list(list)
127 char *list;
128 {
129 register int setautostart, start, stop;
130 register char *pos;
131 char *p;
133 /*
134 * set a byte in the positions array to indicate if a field or
135 * column is to be selected; use +1, it's 1-based, not 0-based.
136 * This parser is less restrictive than the Draft 9 POSIX spec.
137 * POSIX doesn't allow lists that aren't in increasing order or
138 * overlapping lists. We also handle "-3-5" although there's no
139 * real reason too.
140 */
141 for (; p = strtok(list, ", \t"); list = NULL) {
142 setautostart = start = stop = 0;
143 if (*p == '-') {
144 ++p;
145 setautostart = 1;
146 }
147 if (isdigit(*p)) {
148 start = stop = strtol(p, &p, 10);
149 if (setautostart && start > autostart)
150 autostart = start;
151 }
152 if (*p == '-') {
153 if (isdigit(p[1]))
154 stop = strtol(p + 1, &p, 10);
155 if (*p == '-') {
156 ++p;
157 if (!autostop || autostop > stop)
158 autostop = stop;
159 }
160 }
161 if (*p)
162 err("[-cf] list: illegal list value\n");
163 if (!stop || !start)
164 err("[-cf] list: values may not include zero\n");
165 if (stop > _POSIX2_LINE_MAX)
166 err("[-cf] list: %d too large (max %d)\n",
167 stop, _POSIX2_LINE_MAX);
168 if (maxval < stop)
169 maxval = stop;
170 for (pos = positions + start; start++ <= stop; *pos++ = 1);
171 }
173 /* overlapping ranges */
174 if (autostop && maxval > autostop)
175 maxval = autostop;
177 /* set autostart */
178 if (autostart)
179 memset(positions + 1, '1', autostart);
180 }
182 /* ARGSUSED */
183 void
184 c_cut(fp, fname)
185 FILE *fp;
186 char *fname;
187 {
188 register int ch, col;
189 register char *pos;
191 for (;;) {
192 pos = positions + 1;
193 for (col = maxval; col; --col) {
194 if ((ch = getc(fp)) == EOF)
195 return;
196 if (ch == '\n')
197 break;
198 if (*pos++)
199 (void)putchar(ch);
200 }
201 if (ch != '\n')
202 if (autostop)
203 while ((ch = getc(fp)) != EOF && ch != '\n')
204 (void)putchar(ch);
205 else
206 while ((ch = getc(fp)) != EOF && ch != '\n');
207 (void)putchar('\n');
208 }
209 }
211 void
212 f_cut(fp, fname)
213 FILE *fp;
214 char *fname;
215 {
216 register int ch, field, isdelim;
217 register char *pos, *p, sep;
218 int output;
219 char lbuf[_POSIX2_LINE_MAX + 1];
221 for (sep = dchar, output = 0; fgets(lbuf, sizeof(lbuf), fp);) {
222 for (isdelim = 0, p = lbuf;; ++p) {
223 if (!(ch = *p))
224 err("%s: line too long.\n", fname);
225 /* this should work if newline is delimiter */
226 if (ch == sep)
227 isdelim = 1;
228 if (ch == '\n') {
229 if (!isdelim && !sflag)
230 (void)printf("%s", lbuf);
231 break;
232 }
233 }
234 if (!isdelim)
235 continue;
237 pos = positions + 1;
238 for (field = maxval, p = lbuf; field; --field, ++pos) {
239 if (*pos) {
240 if (output++)
241 (void)putchar(sep);
242 while ((ch = *p++) != '\n' && ch != sep)
243 (void)putchar(ch);
244 } else
245 while ((ch = *p++) != '\n' && ch != sep);
246 if (ch == '\n')
247 break;
248 }
249 if (ch != '\n')
250 if (autostop) {
251 if (output)
252 (void)putchar(sep);
253 for (; (ch = *p) != '\n'; ++p)
254 (void)putchar(ch);
255 } else
256 for (; (ch = *p) != '\n'; ++p);
257 (void)putchar('\n');
258 }
259 }
261 void
262 usage()
263 {
264 (void)fprintf(stderr,
265 "usage:\tcut -c list [file1 ...]\n\tcut -f list [-s] [-d delim] [file ...]\n");
266 exit(1);
267 }
269 #if __STDC__
270 #include <stdarg.h>
271 #else
272 #include <varargs.h>
273 #endif
275 void
276 #if __STDC__
277 err(const char *fmt, ...)
278 #else
279 err(fmt, va_alist)
280 char *fmt;
281 va_dcl
282 #endif
283 {
284 va_list ap;
285 #if __STDC__
286 va_start(ap, fmt);
287 #else
288 va_start(ap);
289 #endif
290 (void)fprintf(stderr, "cut: ");
291 (void)vfprintf(stderr, fmt, ap);
292 va_end(ap);
293 (void)fprintf(stderr, "\n");
294 exit(1);
295 /* NOTREACHED */
296 }