date.c revision 1.50 
1/* $NetBSD: date.c,v 1.50 2007/02/04 22:11:13 cbiere 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\n\
36	The Regents of the University of California.  All rights reserved.\n");
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 1.50 2007/02/04 22:11:13 cbiere 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
65static time_t tval;
66static int aflag, jflag, rflag, nflag;
67int retval;
68
69static void badformat(void);
70static void badtime(void);
71static void badvalue(const char *);
72static void setthetime(const char *);
73static void usage(void);
74
75int
76main(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 = strtol(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;
145bad:
146	err(1, "Cannot allocate format buffer");
147}
148
149static void
150badformat(void)
151{
152	warnx("illegal time format");
153	usage();
154}
155
156static void
157badtime(void)
158{
159	errx(EXIT_FAILURE, "illegal time");
160	/* NOTREACHED */
161}
162
163static void
164badvalue(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
172static void
173setthetime(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
316static void
317usage(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