date.c revision 1.46 
1/* $NetBSD: date.c,v 1.46 2006/11/15 03:10:01 jdarrow 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 1.46 2006/11/15 03:10:01 jdarrow 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, "ajnr:u")) != -1) {
87		switch (ch) {
88		case 'a':		/* adjust time slowly */
89			aflag = 1;
90			nflag = 1;
91			break;
92		case 'j':		/* don't set time */
93			jflag = 1;
94			break;
95		case 'n':		/* don't set network */
96			nflag = 1;
97			break;
98		case 'r':		/* user specified seconds */
99			rflag = 1;
100			tval = strtol(optarg, NULL, 0);
101			break;
102		case 'u':		/* do everything in UTC */
103			(void)putenv("TZ=UTC0");
104			break;
105		default:
106			usage();
107		}
108	}
109	argc -= optind;
110	argv += optind;
111
112	if (!rflag && time(&tval) == -1)
113		err(EXIT_FAILURE, "time");
114
115	format = "%a %b %e %H:%M:%S %Z %Y";
116
117	/* allow the operands in any order */
118	if (*argv && **argv == '+') {
119		format = *argv + 1;
120		++argv;
121	}
122
123	if (*argv) {
124		setthetime(*argv);
125		++argv;
126	}
127
128	if (*argv && **argv == '+')
129		format = *argv + 1;
130
131	if ((buf = malloc(bufsiz = 1024)) == NULL)
132		goto bad;
133	while (strftime(buf, bufsiz, format, localtime(&tval)) == 0)
134		if ((buf = realloc(buf, bufsiz <<= 1)) == NULL)
135			goto bad;
136	(void)printf("%s\n", buf);
137	free(buf);
138	return 0;
139bad:
140	err(1, "Cannot allocate format buffer");
141}
142
143static void
144badformat(void)
145{
146	warnx("illegal time format");
147	usage();
148}
149
150static void
151badtime(void)
152{
153	errx(EXIT_FAILURE, "illegal time");
154	/* NOTREACHED */
155}
156
157static void
158badvalue(const char *param)
159{
160	warnx("invalid %s supplied", param);
161	usage();
162}
163
164#define ATOI2(s) ((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))
165
166static void
167setthetime(const char *p)
168{
169	struct timeval tv;
170	time_t new_time;
171	struct tm *lt;
172	const char *dot, *t;
173	int len, yearset;
174
175	for (t = p, dot = NULL; *t; ++t) {
176		if (isdigit((unsigned char)*t))
177			continue;
178		if (*t == '.' && dot == NULL) {
179			dot = t;
180			continue;
181		}
182		badformat();
183	}
184
185	lt = localtime(&tval);
186
187	lt->tm_isdst = -1;			/* Divine correct DST */
188
189	if (dot != NULL) {			/* .ss */
190		len = strlen(dot);
191		if (len != 3)
192			badformat();
193		++dot;
194		lt->tm_sec = ATOI2(dot);
195		if (lt->tm_sec > 61)
196			badvalue("seconds");
197	} else {
198		len = 0;
199		lt->tm_sec = 0;
200	}
201
202	yearset = 0;
203	switch (strlen(p) - len) {
204	case 12:				/* cc */
205		lt->tm_year = ATOI2(p) * 100 - TM_YEAR_BASE;
206		if (lt->tm_year < 0)
207			badtime();
208		yearset = 1;
209		/* FALLTHROUGH */
210	case 10:				/* yy */
211		if (yearset) {
212			lt->tm_year += ATOI2(p);
213		} else {
214			yearset = ATOI2(p);
215			if (yearset < 69)
216				lt->tm_year = yearset + 2000 - TM_YEAR_BASE;
217			else
218				lt->tm_year = yearset + 1900 - TM_YEAR_BASE;
219		}
220		/* FALLTHROUGH */
221	case 8:					/* mm */
222		lt->tm_mon = ATOI2(p);
223		if (lt->tm_mon > 12 || lt->tm_mon == 0)
224			badvalue("month");
225		--lt->tm_mon;			/* time struct is 0 - 11 */
226		/* FALLTHROUGH */
227	case 6:					/* dd */
228		lt->tm_mday = ATOI2(p);
229		switch (lt->tm_mon) {
230		case 0:
231		case 2:
232		case 4:
233		case 6:
234		case 7:
235		case 9:
236		case 11:
237			if (lt->tm_mday > 31 || lt->tm_mday == 0)
238				badvalue("day of month");
239			break;
240		case 3:
241		case 5:
242		case 8:
243		case 10:
244			if (lt->tm_mday > 30 || lt->tm_mday == 0)
245				badvalue("day of month");
246			break;
247		case 1:
248			if (lt->tm_mday > 29 || lt->tm_mday == 0 ||
249			    (lt->tm_mday == 29 &&
250			     !isleap(lt->tm_year + TM_YEAR_BASE)))
251				badvalue("day of month");
252			break;
253		default:
254			badvalue("month");
255			break;
256		}
257		/* FALLTHROUGH */
258	case 4:					/* hh */
259		lt->tm_hour = ATOI2(p);
260		if (lt->tm_hour > 23)
261			badvalue("hour");
262		/* FALLTHROUGH */
263	case 2:					/* mm */
264		lt->tm_min = ATOI2(p);
265		if (lt->tm_min > 59)
266			badvalue("minute");
267		break;
268	case 0:					/* was just .sss */
269		if (len != 0)
270			break;
271		/* FALLTHROUGH */
272	default:
273		badformat();
274	}
275
276	/* convert broken-down time to UTC clock time */
277	if ((new_time = mktime(lt)) == -1)
278		badtime();
279
280	/* if jflag is set, don't actually change the time, just return */
281	if (jflag) {
282		tval = new_time;
283		return;
284	}
285
286	/* set the time */
287	if (nflag || netsettime(new_time)) {
288		logwtmp("|", "date", "");
289		if (aflag) {
290			tv.tv_sec = new_time - tval;
291			tv.tv_usec = 0;
292			if (adjtime(&tv, NULL))
293				err(EXIT_FAILURE, "adjtime");
294		} else {
295			tval = new_time;
296			tv.tv_sec = tval;
297			tv.tv_usec = 0;
298			if (settimeofday(&tv, NULL))
299				err(EXIT_FAILURE, "settimeofday");
300		}
301		logwtmp("{", "date", "");
302	}
303
304	if ((p = getlogin()) == NULL)
305		p = "???";
306	syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
307}
308
309static void
310usage(void)
311{
312	(void)fprintf(stderr,
313	    "usage: %s [-ajnu] [-r seconds] [+format]", getprogname());
314	(void)fprintf(stderr, " [[[[[[CC]yy]mm]dd]HH]MM[.SS]]\n");
315	exit(EXIT_FAILURE);
316	/* NOTREACHED */
317}
318