xref: /openbsd-src/usr.bin/cut/cut.c (revision 898184e3e61f9129feb5978fad5a8c6865f00b92)
1 /*	$OpenBSD: cut.c,v 1.15 2010/01/23 00:32:12 schwarze Exp $	*/
2 /*	$NetBSD: cut.c,v 1.9 1995/09/02 05:59:23 jtc Exp $	*/
3 
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  */
35 
36 #include <ctype.h>
37 #include <err.h>
38 #include <errno.h>
39 #include <limits.h>
40 #include <locale.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45 
46 int	cflag;
47 char	dchar;
48 int	dflag;
49 int	fflag;
50 int	sflag;
51 
52 void	c_cut(FILE *, char *);
53 void	f_cut(FILE *, char *);
54 void	get_list(char *);
55 void	usage(void);
56 
57 int
58 main(int argc, char *argv[])
59 {
60 	FILE *fp;
61 	void (*fcn)(FILE *, char *);
62 	int ch;
63 
64 	setlocale (LC_ALL, "");
65 
66 	dchar = '\t';			/* default delimiter is \t */
67 
68 	/* Since we don't support multi-byte characters, the -c and -b
69 	   options are equivalent, and the -n option is meaningless. */
70 	while ((ch = getopt(argc, argv, "b:c:d:f:sn")) != -1)
71 		switch(ch) {
72 		case 'b':
73 		case 'c':
74 			fcn = c_cut;
75 			get_list(optarg);
76 			cflag = 1;
77 			break;
78 		case 'd':
79 			dchar = *optarg;
80 			dflag = 1;
81 			break;
82 		case 'f':
83 			get_list(optarg);
84 			fcn = f_cut;
85 			fflag = 1;
86 			break;
87 		case 's':
88 			sflag = 1;
89 			break;
90 		case 'n':
91 			break;
92 		case '?':
93 		default:
94 			usage();
95 		}
96 	argc -= optind;
97 	argv += optind;
98 
99 	if (fflag) {
100 		if (cflag)
101 			usage();
102 	} else if (!cflag || dflag || sflag)
103 		usage();
104 
105 	if (*argv)
106 		for (; *argv; ++argv) {
107 			if (!(fp = fopen(*argv, "r")))
108 				err(1, "%s", *argv);
109 			fcn(fp, *argv);
110 			(void)fclose(fp);
111 		}
112 	else
113 		fcn(stdin, "stdin");
114 	exit(0);
115 }
116 
117 int autostart, autostop, maxval;
118 
119 char positions[_POSIX2_LINE_MAX + 1];
120 
121 void
122 get_list(char *list)
123 {
124 	int setautostart, start, stop;
125 	char *pos;
126 	char *p;
127 
128 	/*
129 	 * set a byte in the positions array to indicate if a field or
130 	 * column is to be selected; use +1, it's 1-based, not 0-based.
131 	 * This parser is less restrictive than the Draft 9 POSIX spec.
132 	 * POSIX doesn't allow lists that aren't in increasing order or
133 	 * overlapping lists.  We also handle "-3-5" although there's no
134 	 * real reason too.
135 	 */
136 	while ((p = strsep(&list, ", \t"))) {
137 		setautostart = start = stop = 0;
138 		if (*p == '-') {
139 			++p;
140 			setautostart = 1;
141 		}
142 		if (isdigit(*p)) {
143 			start = stop = strtol(p, &p, 10);
144 			if (setautostart && start > autostart)
145 				autostart = start;
146 		}
147 		if (*p == '-') {
148 			if (isdigit(p[1]))
149 				stop = strtol(p + 1, &p, 10);
150 			if (*p == '-') {
151 				++p;
152 				if (!autostop || autostop > stop)
153 					autostop = stop;
154 			}
155 		}
156 		if (*p)
157 			errx(1, "[-bcf] list: illegal list value");
158 		if (!stop || !start)
159 			errx(1, "[-bcf] list: values may not include zero");
160 		if (stop > _POSIX2_LINE_MAX)
161 			errx(1, "[-bcf] list: %d too large (max %d)",
162 			    stop, _POSIX2_LINE_MAX);
163 		if (maxval < stop)
164 			maxval = stop;
165 		for (pos = positions + start; start++ <= stop; *pos++ = 1)
166 			;
167 	}
168 
169 	/* overlapping ranges */
170 	if (autostop && maxval > autostop)
171 		maxval = autostop;
172 
173 	/* set autostart */
174 	if (autostart)
175 		memset(positions + 1, '1', autostart);
176 }
177 
178 /* ARGSUSED */
179 void
180 c_cut(FILE *fp, char *fname)
181 {
182 	int ch, col;
183 	char *pos;
184 
185 	for (;;) {
186 		pos = positions + 1;
187 		for (col = maxval; col; --col) {
188 			if ((ch = getc(fp)) == EOF)
189 				return;
190 			if (ch == '\n')
191 				break;
192 			if (*pos++)
193 				(void)putchar(ch);
194 		}
195 		if (ch != '\n') {
196 			if (autostop)
197 				while ((ch = getc(fp)) != EOF && ch != '\n')
198 					(void)putchar(ch);
199 			else
200 				while ((ch = getc(fp)) != EOF && ch != '\n')
201 					;
202 		}
203 		(void)putchar('\n');
204 	}
205 }
206 
207 void
208 f_cut(FILE *fp, char *fname)
209 {
210 	int ch, field, isdelim;
211 	char *pos, *p, sep;
212 	int output;
213 	size_t len;
214 	char *lbuf, *tbuf;
215 
216 	for (sep = dchar, tbuf = NULL; (lbuf = fgetln(fp, &len));) {
217 		output = 0;
218 		if (lbuf[len - 1] != '\n') {
219 			/* no newline at the end of the last line so add one */
220 			if ((tbuf = (char *)malloc(len + 1)) == NULL)
221 				err(1, NULL);
222 			memcpy(tbuf, lbuf, len);
223 			tbuf[len] = '\n';
224 			lbuf = tbuf;
225 		}
226 		for (isdelim = 0, p = lbuf;; ++p) {
227 			ch = *p;
228 			/* this should work if newline is delimiter */
229 			if (ch == sep)
230 				isdelim = 1;
231 			if (ch == '\n') {
232 				if (!isdelim && !sflag)
233 					(void)fwrite(lbuf, len, 1, stdout);
234 				break;
235 			}
236 		}
237 		if (!isdelim)
238 			continue;
239 
240 		pos = positions + 1;
241 		for (field = maxval, p = lbuf; field; --field, ++pos) {
242 			if (*pos) {
243 				if (output++)
244 					(void)putchar(sep);
245 				while ((ch = *p++) != '\n' && ch != sep)
246 					(void)putchar(ch);
247 			} else
248 				while ((ch = *p++) != '\n' && ch != sep)
249 					;
250 			if (ch == '\n')
251 				break;
252 		}
253 		if (ch != '\n') {
254 			if (autostop) {
255 				if (output)
256 					(void)putchar(sep);
257 				for (; (ch = *p) != '\n'; ++p)
258 					(void)putchar(ch);
259 			} else
260 				for (; (ch = *p) != '\n'; ++p)
261 					;
262 		}
263 		(void)putchar('\n');
264 	}
265 	if (tbuf)
266 		free(tbuf);
267 }
268 
269 void
270 usage(void)
271 {
272 	(void)fprintf(stderr,
273 	    "usage: cut -b list [-n] [file ...]\n"
274 	    "       cut -c list [file ...]\n"
275 	    "       cut -f list [-s] [-d delim] [file ...]\n");
276 	exit(1);
277 }
278