xref: /netbsd-src/bin/date/date.c (revision 274254cdae52594c1aa480a736aef78313d15c9c)
1 /* $NetBSD: date.c,v 1.52 2008/07/20 00:52:39 lukem Exp $ */
2 
3 /*
4  * Copyright (c) 1985, 1987, 1988, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT(
35 "@(#) Copyright (c) 1985, 1987, 1988, 1993\
36  The Regents of the University of California.  All rights reserved.");
37 #endif /* not lint */
38 
39 #ifndef lint
40 #if 0
41 static char sccsid[] = "@(#)date.c	8.2 (Berkeley) 4/28/95";
42 #else
43 __RCSID("$NetBSD: date.c,v 1.52 2008/07/20 00:52:39 lukem Exp $");
44 #endif
45 #endif /* not lint */
46 
47 #include <sys/param.h>
48 #include <sys/time.h>
49 
50 #include <ctype.h>
51 #include <err.h>
52 #include <fcntl.h>
53 #include <locale.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <syslog.h>
58 #include <time.h>
59 #include <tzfile.h>
60 #include <unistd.h>
61 #include <util.h>
62 
63 #include "extern.h"
64 
65 static time_t tval;
66 static int aflag, jflag, rflag, nflag;
67 int retval;
68 
69 static void badformat(void);
70 static void badtime(void);
71 static void badvalue(const char *);
72 static void setthetime(const char *);
73 static void usage(void);
74 
75 int
76 main(int argc, char *argv[])
77 {
78 	char *buf;
79 	size_t bufsiz;
80 	const char *format;
81 	int ch;
82 
83 	setprogname(argv[0]);
84 	(void)setlocale(LC_ALL, "");
85 
86 	while ((ch = getopt(argc, argv, "ad:jnr:u")) != -1) {
87 		switch (ch) {
88 		case 'a':		/* adjust time slowly */
89 			aflag = 1;
90 			nflag = 1;
91 			break;
92 		case 'd':
93 			rflag = 1;
94 			tval = parsedate(optarg, NULL, NULL);
95 			if (tval == -1)
96 				errx(1, "Cannot parse `%s'", optarg);
97 			break;
98 		case 'j':		/* don't set time */
99 			jflag = 1;
100 			break;
101 		case 'n':		/* don't set network */
102 			nflag = 1;
103 			break;
104 		case 'r':		/* user specified seconds */
105 			rflag = 1;
106 			tval = strtoll(optarg, NULL, 0);
107 			break;
108 		case 'u':		/* do everything in UTC */
109 			(void)putenv("TZ=UTC0");
110 			break;
111 		default:
112 			usage();
113 		}
114 	}
115 	argc -= optind;
116 	argv += optind;
117 
118 	if (!rflag && time(&tval) == -1)
119 		err(EXIT_FAILURE, "time");
120 
121 	format = "%a %b %e %H:%M:%S %Z %Y";
122 
123 	/* allow the operands in any order */
124 	if (*argv && **argv == '+') {
125 		format = *argv + 1;
126 		++argv;
127 	}
128 
129 	if (*argv) {
130 		setthetime(*argv);
131 		++argv;
132 	}
133 
134 	if (*argv && **argv == '+')
135 		format = *argv + 1;
136 
137 	if ((buf = malloc(bufsiz = 1024)) == NULL)
138 		goto bad;
139 	while (strftime(buf, bufsiz, format, localtime(&tval)) == 0)
140 		if ((buf = realloc(buf, bufsiz <<= 1)) == NULL)
141 			goto bad;
142 	(void)printf("%s\n", buf);
143 	free(buf);
144 	return 0;
145 bad:
146 	err(1, "Cannot allocate format buffer");
147 }
148 
149 static void
150 badformat(void)
151 {
152 	warnx("illegal time format");
153 	usage();
154 }
155 
156 static void
157 badtime(void)
158 {
159 	errx(EXIT_FAILURE, "illegal time");
160 	/* NOTREACHED */
161 }
162 
163 static void
164 badvalue(const char *param)
165 {
166 	warnx("invalid %s supplied", param);
167 	usage();
168 }
169 
170 #define ATOI2(s) ((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))
171 
172 static void
173 setthetime(const char *p)
174 {
175 	struct timeval tv;
176 	time_t new_time;
177 	struct tm *lt;
178 	const char *dot, *t;
179 	size_t len;
180 	int yearset;
181 
182 	for (t = p, dot = NULL; *t; ++t) {
183 		if (isdigit((unsigned char)*t))
184 			continue;
185 		if (*t == '.' && dot == NULL) {
186 			dot = t;
187 			continue;
188 		}
189 		badformat();
190 	}
191 
192 	lt = localtime(&tval);
193 
194 	lt->tm_isdst = -1;			/* Divine correct DST */
195 
196 	if (dot != NULL) {			/* .ss */
197 		len = strlen(dot);
198 		if (len != 3)
199 			badformat();
200 		++dot;
201 		lt->tm_sec = ATOI2(dot);
202 		if (lt->tm_sec > 61)
203 			badvalue("seconds");
204 	} else {
205 		len = 0;
206 		lt->tm_sec = 0;
207 	}
208 
209 	yearset = 0;
210 	switch (strlen(p) - len) {
211 	case 12:				/* cc */
212 		lt->tm_year = ATOI2(p) * 100 - TM_YEAR_BASE;
213 		if (lt->tm_year < 0)
214 			badtime();
215 		yearset = 1;
216 		/* FALLTHROUGH */
217 	case 10:				/* yy */
218 		if (yearset) {
219 			lt->tm_year += ATOI2(p);
220 		} else {
221 			yearset = ATOI2(p);
222 			if (yearset < 69)
223 				lt->tm_year = yearset + 2000 - TM_YEAR_BASE;
224 			else
225 				lt->tm_year = yearset + 1900 - TM_YEAR_BASE;
226 		}
227 		/* FALLTHROUGH */
228 	case 8:					/* mm */
229 		lt->tm_mon = ATOI2(p);
230 		if (lt->tm_mon > 12 || lt->tm_mon == 0)
231 			badvalue("month");
232 		--lt->tm_mon;			/* time struct is 0 - 11 */
233 		/* FALLTHROUGH */
234 	case 6:					/* dd */
235 		lt->tm_mday = ATOI2(p);
236 		switch (lt->tm_mon) {
237 		case 0:
238 		case 2:
239 		case 4:
240 		case 6:
241 		case 7:
242 		case 9:
243 		case 11:
244 			if (lt->tm_mday > 31 || lt->tm_mday == 0)
245 				badvalue("day of month");
246 			break;
247 		case 3:
248 		case 5:
249 		case 8:
250 		case 10:
251 			if (lt->tm_mday > 30 || lt->tm_mday == 0)
252 				badvalue("day of month");
253 			break;
254 		case 1:
255 			if (lt->tm_mday > 29 || lt->tm_mday == 0 ||
256 			    (lt->tm_mday == 29 &&
257 			     !isleap(lt->tm_year + TM_YEAR_BASE)))
258 				badvalue("day of month");
259 			break;
260 		default:
261 			badvalue("month");
262 			break;
263 		}
264 		/* FALLTHROUGH */
265 	case 4:					/* hh */
266 		lt->tm_hour = ATOI2(p);
267 		if (lt->tm_hour > 23)
268 			badvalue("hour");
269 		/* FALLTHROUGH */
270 	case 2:					/* mm */
271 		lt->tm_min = ATOI2(p);
272 		if (lt->tm_min > 59)
273 			badvalue("minute");
274 		break;
275 	case 0:					/* was just .sss */
276 		if (len != 0)
277 			break;
278 		/* FALLTHROUGH */
279 	default:
280 		badformat();
281 	}
282 
283 	/* convert broken-down time to UTC clock time */
284 	if ((new_time = mktime(lt)) == -1)
285 		badtime();
286 
287 	/* if jflag is set, don't actually change the time, just return */
288 	if (jflag) {
289 		tval = new_time;
290 		return;
291 	}
292 
293 	/* set the time */
294 	if (nflag || netsettime(new_time)) {
295 		logwtmp("|", "date", "");
296 		if (aflag) {
297 			tv.tv_sec = new_time - tval;
298 			tv.tv_usec = 0;
299 			if (adjtime(&tv, NULL))
300 				err(EXIT_FAILURE, "adjtime");
301 		} else {
302 			tval = new_time;
303 			tv.tv_sec = tval;
304 			tv.tv_usec = 0;
305 			if (settimeofday(&tv, NULL))
306 				err(EXIT_FAILURE, "settimeofday");
307 		}
308 		logwtmp("{", "date", "");
309 	}
310 
311 	if ((p = getlogin()) == NULL)
312 		p = "???";
313 	syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
314 }
315 
316 static void
317 usage(void)
318 {
319 	(void)fprintf(stderr,
320 	    "usage: %s [-ajnu] [-d date] [-r seconds] [+format]", getprogname());
321 	(void)fprintf(stderr, " [[[[[[CC]yy]mm]dd]HH]MM[.SS]]\n");
322 	exit(EXIT_FAILURE);
323 	/* NOTREACHED */
324 }
325