date.c revision 1.43 
1/* $NetBSD: date.c,v 1.43 2006/07/23 20:39:10 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\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 1.43 2006/07/23 20:39:10 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 <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, rflag, nflag;
67int retval;
68
69static void badformat(void);
70static void badtime(void);
71static void setthetime(const char *);
72static void usage(void);
73
74int
75main(int argc, char *argv[])
76{
77	char *buf;
78	size_t bufsiz;
79	const char *format;
80	int ch;
81
82	setprogname(argv[0]);
83	(void)setlocale(LC_ALL, "");
84
85	while ((ch = getopt(argc, argv, "anr:u")) != -1) {
86		switch (ch) {
87		case 'a':		/* adjust time slowly */
88			aflag = 1;
89			nflag = 1;
90			break;
91		case 'n':		/* don't set network */
92			nflag = 1;
93			break;
94		case 'r':		/* user specified seconds */
95			rflag = 1;
96			tval = strtol(optarg, NULL, 0);
97			break;
98		case 'u':		/* do everything in UTC */
99			(void)putenv("TZ=UTC0");
100			break;
101		default:
102			usage();
103		}
104	}
105	argc -= optind;
106	argv += optind;
107
108	if (!rflag && time(&tval) == -1)
109		err(EXIT_FAILURE, "time");
110
111	format = "%a %b %e %H:%M:%S %Z %Y";
112
113	/* allow the operands in any order */
114	if (*argv && **argv == '+') {
115		format = *argv + 1;
116		++argv;
117	}
118
119	if (*argv) {
120		setthetime(*argv);
121		++argv;
122	}
123
124	if (*argv && **argv == '+')
125		format = *argv + 1;
126
127	if ((buf = malloc(bufsiz = 1024)) == NULL)
128		goto bad;
129	while (strftime(buf, bufsiz, format, localtime(&tval)) == 0)
130		if ((buf = realloc(buf, bufsiz <<= 1)) == NULL)
131			goto bad;
132	(void)printf("%s\n", buf);
133	free(buf);
134	return 0;
135bad:
136	err(1, "Cannot allocate format buffer");
137}
138
139static void
140badformat(void)
141{
142	warnx("illegal time format");
143	usage();
144}
145
146static void
147badtime(void)
148{
149	errx(EXIT_FAILURE, "illegal time");
150	/* NOTREACHED */
151}
152
153#define ATOI2(s) ((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))
154
155static void
156setthetime(const char *p)
157{
158	struct timeval tv;
159	time_t new_time;
160	struct tm *lt;
161	const char *dot, *t;
162	int len, yearset;
163
164	for (t = p, dot = NULL; *t; ++t) {
165		if (isdigit((unsigned char)*t))
166			continue;
167		if (*t == '.' && dot == NULL) {
168			dot = t;
169			continue;
170		}
171		badformat();
172	}
173
174	lt = localtime(&tval);
175
176	lt->tm_isdst = -1;			/* Divine correct DST */
177
178	if (dot != NULL) {			/* .ss */
179		len = strlen(dot);
180		if (len != 3)
181			badformat();
182		++dot;
183		lt->tm_sec = ATOI2(dot);
184	} else {
185		len = 0;
186		lt->tm_sec = 0;
187	}
188
189	yearset = 0;
190	switch (strlen(p) - len) {
191	case 12:				/* cc */
192		lt->tm_year = ATOI2(p) * 100 - TM_YEAR_BASE;
193		yearset = 1;
194		/* FALLTHROUGH */
195	case 10:				/* yy */
196		if (yearset) {
197			lt->tm_year += ATOI2(p);
198		} else {
199			yearset = ATOI2(p);
200			if (yearset < 69)
201				lt->tm_year = yearset + 2000 - TM_YEAR_BASE;
202			else
203				lt->tm_year = yearset + 1900 - TM_YEAR_BASE;
204		}
205		/* FALLTHROUGH */
206	case 8:					/* mm */
207		lt->tm_mon = ATOI2(p);
208		--lt->tm_mon;			/* time struct is 0 - 11 */
209		/* FALLTHROUGH */
210	case 6:					/* dd */
211		lt->tm_mday = ATOI2(p);
212		/* FALLTHROUGH */
213	case 4:					/* hh */
214		lt->tm_hour = ATOI2(p);
215		/* FALLTHROUGH */
216	case 2:					/* mm */
217		lt->tm_min = ATOI2(p);
218		break;
219	case 0:					/* was just .sss */
220		if (len != 0)
221			break;
222		/* FALLTHROUGH */
223	default:
224		badformat();
225	}
226
227	/* convert broken-down time to UTC clock time */
228	if ((new_time = mktime(lt)) == -1)
229		badtime();
230
231	/* set the time */
232	if (nflag || netsettime(new_time)) {
233		logwtmp("|", "date", "");
234		if (aflag) {
235			tv.tv_sec = new_time - tval;
236			tv.tv_usec = 0;
237			if (adjtime(&tv, NULL))
238				err(EXIT_FAILURE, "date: adjtime");
239		} else {
240			tval = new_time;
241			tv.tv_sec = tval;
242			tv.tv_usec = 0;
243			if (settimeofday(&tv, NULL))
244				err(EXIT_FAILURE, "date: settimeofday");
245		}
246		logwtmp("{", "date", "");
247	}
248
249	if ((p = getlogin()) == NULL)
250		p = "???";
251	syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
252}
253
254static void
255usage(void)
256{
257	(void)fprintf(stderr,
258	    "usage: %s [-u] [-r seconds] [+format]\n", getprogname());
259	(void)fprintf(stderr, "       %s [-anu] [[[[[cc]yy]mm]dd]hh]mm[.ss]\n",
260	    getprogname());
261	exit(EXIT_FAILURE);
262	/* NOTREACHED */
263}
264