date.c revision 1.59 
1/* $NetBSD: date.c,v 1.59 2011/01/29 02:16:52 christos 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
41static char sccsid[] = "@(#)date.c	8.2 (Berkeley) 4/28/95";
42#else
43__RCSID("$NetBSD: date.c,v 1.59 2011/01/29 02:16:52 christos 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 <errno.h>
54#include <locale.h>
55#include <stdio.h>
56#include <stdlib.h>
57#include <string.h>
58#include <syslog.h>
59#include <time.h>
60#include <tzfile.h>
61#include <unistd.h>
62#include <util.h>
63
64#include "extern.h"
65
66static time_t tval;
67static int aflag, jflag, rflag, nflag;
68
69static void badformat(void);
70static void badtime(void);
71static void badvalue(const char *);
72static void setthetime(const char *);
73static void usage(void) __attribute__((__noreturn__));
74
75int
76main(int argc, char *argv[])
77{
78	char *buf;
79	size_t bufsiz;
80	const char *format;
81	int ch;
82	long long val;
83	struct tm *tm;
84
85	setprogname(argv[0]);
86	(void)setlocale(LC_ALL, "");
87
88	while ((ch = getopt(argc, argv, "ad:jnr:u")) != -1) {
89		switch (ch) {
90		case 'a':		/* adjust time slowly */
91			aflag = 1;
92			nflag = 1;
93			break;
94		case 'd':
95			rflag = 1;
96			tval = parsedate(optarg, NULL, NULL);
97			if (tval == -1)
98badarg:				 errx(EXIT_FAILURE,
99				    "Cannot parse `%s'", optarg);
100			break;
101		case 'j':		/* don't set time */
102			jflag = 1;
103			break;
104		case 'n':		/* don't set network */
105			nflag = 1;
106			break;
107		case 'r':		/* user specified seconds */
108			errno = 0;
109			val = strtoll(optarg, &buf, 0);
110			if (optarg[0] == '\0' || *buf != '\0')
111				goto badarg;
112			if (errno == ERANGE && (val == LLONG_MAX ||
113			    val == LLONG_MIN))
114				err(EXIT_FAILURE, "Bad number `%s'", optarg);
115			rflag = 1;
116			tval = (time_t)val;
117			break;
118		case 'u':		/* do everything in UTC */
119			(void)setenv("TZ", "UTC0", 1);
120			break;
121		default:
122			usage();
123		}
124	}
125	argc -= optind;
126	argv += optind;
127
128	if (!rflag && time(&tval) == -1)
129		err(EXIT_FAILURE, "time");
130
131
132	/* allow the operands in any order */
133	if (*argv && **argv == '+') {
134		format = *argv;
135		++argv;
136	} else
137		format = "+%a %b %e %H:%M:%S %Z %Y";
138
139	if (*argv) {
140		setthetime(*argv);
141		++argv;
142	}
143
144	if (*argv && **argv == '+')
145		format = *argv;
146
147	if ((buf = malloc(bufsiz = 1024)) == NULL)
148		goto bad;
149
150	if ((tm = localtime(&tval)) == NULL)
151		err(EXIT_FAILURE, "localtime %lld failed", (long long)tval);
152
153	while (strftime(buf, bufsiz, format, tm) == 0)
154		if ((buf = realloc(buf, bufsiz <<= 1)) == NULL)
155			goto bad;
156
157	(void)printf("%s\n", buf + 1);
158	free(buf);
159	return 0;
160bad:
161	err(EXIT_FAILURE, "Cannot allocate format buffer");
162}
163
164static void
165badformat(void)
166{
167	warnx("illegal time format");
168	usage();
169}
170
171static void
172badtime(void)
173{
174	errx(EXIT_FAILURE, "illegal time");
175	/* NOTREACHED */
176}
177
178static void
179badvalue(const char *param)
180{
181	warnx("invalid %s supplied", param);
182	usage();
183}
184
185#define ATOI2(s) ((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))
186
187static void
188setthetime(const char *p)
189{
190	struct timeval tv;
191	time_t new_time;
192	struct tm *lt;
193	const char *dot, *t;
194	size_t len;
195	int yearset;
196
197	for (t = p, dot = NULL; *t; ++t) {
198		if (isdigit((unsigned char)*t))
199			continue;
200		if (*t == '.' && dot == NULL) {
201			dot = t;
202			continue;
203		}
204		badformat();
205	}
206
207	if ((lt = localtime(&tval)) == NULL)
208		err(EXIT_FAILURE, "localtime %lld failed", (long long)tval);
209
210	lt->tm_isdst = -1;			/* Divine correct DST */
211
212	if (dot != NULL) {			/* .ss */
213		len = strlen(dot);
214		if (len != 3)
215			badformat();
216		++dot;
217		lt->tm_sec = ATOI2(dot);
218		if (lt->tm_sec > 61)
219			badvalue("seconds");
220	} else {
221		len = 0;
222		lt->tm_sec = 0;
223	}
224
225	yearset = 0;
226	switch (strlen(p) - len) {
227	case 12:				/* cc */
228		lt->tm_year = ATOI2(p) * 100 - TM_YEAR_BASE;
229		if (lt->tm_year < 0)
230			badtime();
231		yearset = 1;
232		/* FALLTHROUGH */
233	case 10:				/* yy */
234		if (yearset) {
235			lt->tm_year += ATOI2(p);
236		} else {
237			yearset = ATOI2(p);
238			if (yearset < 69)
239				lt->tm_year = yearset + 2000 - TM_YEAR_BASE;
240			else
241				lt->tm_year = yearset + 1900 - TM_YEAR_BASE;
242		}
243		/* FALLTHROUGH */
244	case 8:					/* mm */
245		lt->tm_mon = ATOI2(p);
246		if (lt->tm_mon > 12 || lt->tm_mon == 0)
247			badvalue("month");
248		--lt->tm_mon;			/* time struct is 0 - 11 */
249		/* FALLTHROUGH */
250	case 6:					/* dd */
251		lt->tm_mday = ATOI2(p);
252		switch (lt->tm_mon) {
253		case 0:
254		case 2:
255		case 4:
256		case 6:
257		case 7:
258		case 9:
259		case 11:
260			if (lt->tm_mday > 31 || lt->tm_mday == 0)
261				badvalue("day of month");
262			break;
263		case 3:
264		case 5:
265		case 8:
266		case 10:
267			if (lt->tm_mday > 30 || lt->tm_mday == 0)
268				badvalue("day of month");
269			break;
270		case 1:
271			if (lt->tm_mday > 29 || lt->tm_mday == 0 ||
272			    (lt->tm_mday == 29 &&
273			     !isleap(lt->tm_year + TM_YEAR_BASE)))
274				badvalue("day of month");
275			break;
276		default:
277			badvalue("month");
278			break;
279		}
280		/* FALLTHROUGH */
281	case 4:					/* hh */
282		lt->tm_hour = ATOI2(p);
283		if (lt->tm_hour > 23)
284			badvalue("hour");
285		/* FALLTHROUGH */
286	case 2:					/* mm */
287		lt->tm_min = ATOI2(p);
288		if (lt->tm_min > 59)
289			badvalue("minute");
290		break;
291	case 0:					/* was just .sss */
292		if (len != 0)
293			break;
294		/* FALLTHROUGH */
295	default:
296		badformat();
297	}
298
299	/* convert broken-down time to UTC clock time */
300	if ((new_time = mktime(lt)) == -1)
301		badtime();
302
303	/* if jflag is set, don't actually change the time, just return */
304	if (jflag) {
305		tval = new_time;
306		return;
307	}
308
309	/* set the time */
310	if (nflag || netsettime(new_time)) {
311		logwtmp("|", "date", "");
312		if (aflag) {
313			tv.tv_sec = new_time - tval;
314			tv.tv_usec = 0;
315			if (adjtime(&tv, NULL))
316				err(EXIT_FAILURE, "adjtime");
317		} else {
318			tval = new_time;
319			tv.tv_sec = tval;
320			tv.tv_usec = 0;
321			if (settimeofday(&tv, NULL))
322				err(EXIT_FAILURE, "settimeofday");
323		}
324		logwtmp("{", "date", "");
325	}
326
327	if ((p = getlogin()) == NULL)
328		p = "???";
329	syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
330}
331
332static void
333usage(void)
334{
335	(void)fprintf(stderr,
336	    "Usage: %s [-ajnu] [-d date] [-r seconds] [+format]",
337	    getprogname());
338	(void)fprintf(stderr, " [[[[[[CC]yy]mm]dd]HH]MM[.SS]]\n");
339	exit(EXIT_FAILURE);
340	/* NOTREACHED */
341}
342