date.c revision 1.56 
1/* $NetBSD: date.c,v 1.56 2010/12/11 16:57:51 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 1.56 2010/12/11 16:57:51 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
84	setprogname(argv[0]);
85	(void)setlocale(LC_ALL, "");
86
87	while ((ch = getopt(argc, argv, "ad:jnr:u")) != -1) {
88		switch (ch) {
89		case 'a':		/* adjust time slowly */
90			aflag = 1;
91			nflag = 1;
92			break;
93		case 'd':
94			rflag = 1;
95			tval = parsedate(optarg, NULL, NULL);
96			if (tval == -1)
97badarg:				 errx(EXIT_FAILURE,
98				    "Cannot parse `%s'", optarg);
99			break;
100		case 'j':		/* don't set time */
101			jflag = 1;
102			break;
103		case 'n':		/* don't set network */
104			nflag = 1;
105			break;
106		case 'r':		/* user specified seconds */
107			errno = 0;
108			val = strtoll(optarg, &buf, 0);
109			if (optarg[0] == '\0' || *buf != '\0')
110				goto badarg;
111			if (errno == ERANGE && (val == LLONG_MAX ||
112			    val == LLONG_MIN))
113				err(EXIT_FAILURE, "Bad number `%s'", optarg);
114			rflag = 1;
115			tval = (time_t)val;
116			break;
117		case 'u':		/* do everything in UTC */
118			(void)setenv("TZ", "UTC0", 1);
119			break;
120		default:
121			usage();
122		}
123	}
124	argc -= optind;
125	argv += optind;
126
127	if (!rflag && time(&tval) == -1)
128		err(EXIT_FAILURE, "time");
129
130
131	/* allow the operands in any order */
132	if (*argv && **argv == '+') {
133		format = *argv;
134		++argv;
135	} else
136		format = "+%a %b %e %H:%M:%S %Z %Y";
137
138	if (*argv) {
139		setthetime(*argv);
140		++argv;
141	}
142
143	if (*argv && **argv == '+')
144		format = *argv;
145
146	if ((buf = malloc(bufsiz = 1024)) == NULL)
147		goto bad;
148	while (strftime(buf, bufsiz, format, localtime(&tval)) == 0)
149		if ((buf = realloc(buf, bufsiz <<= 1)) == NULL)
150			goto bad;
151	(void)printf("%s\n", buf+1);
152	free(buf);
153	return 0;
154bad:
155	err(EXIT_FAILURE, "Cannot allocate format buffer");
156}
157
158static void
159badformat(void)
160{
161	warnx("illegal time format");
162	usage();
163}
164
165static void
166badtime(void)
167{
168	errx(EXIT_FAILURE, "illegal time");
169	/* NOTREACHED */
170}
171
172static void
173badvalue(const char *param)
174{
175	warnx("invalid %s supplied", param);
176	usage();
177}
178
179#define ATOI2(s) ((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))
180
181static void
182setthetime(const char *p)
183{
184	struct timeval tv;
185	time_t new_time;
186	struct tm *lt;
187	const char *dot, *t;
188	size_t len;
189	int yearset;
190
191	for (t = p, dot = NULL; *t; ++t) {
192		if (isdigit((unsigned char)*t))
193			continue;
194		if (*t == '.' && dot == NULL) {
195			dot = t;
196			continue;
197		}
198		badformat();
199	}
200
201	lt = localtime(&tval);
202
203	lt->tm_isdst = -1;			/* Divine correct DST */
204
205	if (dot != NULL) {			/* .ss */
206		len = strlen(dot);
207		if (len != 3)
208			badformat();
209		++dot;
210		lt->tm_sec = ATOI2(dot);
211		if (lt->tm_sec > 61)
212			badvalue("seconds");
213	} else {
214		len = 0;
215		lt->tm_sec = 0;
216	}
217
218	yearset = 0;
219	switch (strlen(p) - len) {
220	case 12:				/* cc */
221		lt->tm_year = ATOI2(p) * 100 - TM_YEAR_BASE;
222		if (lt->tm_year < 0)
223			badtime();
224		yearset = 1;
225		/* FALLTHROUGH */
226	case 10:				/* yy */
227		if (yearset) {
228			lt->tm_year += ATOI2(p);
229		} else {
230			yearset = ATOI2(p);
231			if (yearset < 69)
232				lt->tm_year = yearset + 2000 - TM_YEAR_BASE;
233			else
234				lt->tm_year = yearset + 1900 - TM_YEAR_BASE;
235		}
236		/* FALLTHROUGH */
237	case 8:					/* mm */
238		lt->tm_mon = ATOI2(p);
239		if (lt->tm_mon > 12 || lt->tm_mon == 0)
240			badvalue("month");
241		--lt->tm_mon;			/* time struct is 0 - 11 */
242		/* FALLTHROUGH */
243	case 6:					/* dd */
244		lt->tm_mday = ATOI2(p);
245		switch (lt->tm_mon) {
246		case 0:
247		case 2:
248		case 4:
249		case 6:
250		case 7:
251		case 9:
252		case 11:
253			if (lt->tm_mday > 31 || lt->tm_mday == 0)
254				badvalue("day of month");
255			break;
256		case 3:
257		case 5:
258		case 8:
259		case 10:
260			if (lt->tm_mday > 30 || lt->tm_mday == 0)
261				badvalue("day of month");
262			break;
263		case 1:
264			if (lt->tm_mday > 29 || lt->tm_mday == 0 ||
265			    (lt->tm_mday == 29 &&
266			     !isleap(lt->tm_year + TM_YEAR_BASE)))
267				badvalue("day of month");
268			break;
269		default:
270			badvalue("month");
271			break;
272		}
273		/* FALLTHROUGH */
274	case 4:					/* hh */
275		lt->tm_hour = ATOI2(p);
276		if (lt->tm_hour > 23)
277			badvalue("hour");
278		/* FALLTHROUGH */
279	case 2:					/* mm */
280		lt->tm_min = ATOI2(p);
281		if (lt->tm_min > 59)
282			badvalue("minute");
283		break;
284	case 0:					/* was just .sss */
285		if (len != 0)
286			break;
287		/* FALLTHROUGH */
288	default:
289		badformat();
290	}
291
292	/* convert broken-down time to UTC clock time */
293	if ((new_time = mktime(lt)) == -1)
294		badtime();
295
296	/* if jflag is set, don't actually change the time, just return */
297	if (jflag) {
298		tval = new_time;
299		return;
300	}
301
302	/* set the time */
303	if (nflag || netsettime(new_time)) {
304		logwtmp("|", "date", "");
305		if (aflag) {
306			tv.tv_sec = new_time - tval;
307			tv.tv_usec = 0;
308			if (adjtime(&tv, NULL))
309				err(EXIT_FAILURE, "adjtime");
310		} else {
311			tval = new_time;
312			tv.tv_sec = tval;
313			tv.tv_usec = 0;
314			if (settimeofday(&tv, NULL))
315				err(EXIT_FAILURE, "settimeofday");
316		}
317		logwtmp("{", "date", "");
318	}
319
320	if ((p = getlogin()) == NULL)
321		p = "???";
322	syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
323}
324
325static void
326usage(void)
327{
328	(void)fprintf(stderr,
329	    "Usage: %s [-ajnu] [-d date] [-r seconds] [+format]",
330	    getprogname());
331	(void)fprintf(stderr, " [[[[[[CC]yy]mm]dd]HH]MM[.SS]]\n");
332	exit(EXIT_FAILURE);
333	/* NOTREACHED */
334}
335