date.c revision 1.7 
1/*
2 * Copyright (c) 1985, 1987, 1988 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef lint
35char copyright[] =
36"@(#) Copyright (c) 1985, 1987, 1988 The Regents of the University of California.\n\
37 All rights reserved.\n";
38#endif /* not lint */
39
40#ifndef lint
41/*static char sccsid[] = "from: @(#)date.c	5.5 (Berkeley) 3/18/91";*/
42static char rcsid[] = "$Id: date.c,v 1.7 1993/12/31 19:25:23 jtc Exp $";
43#endif /* not lint */
44
45#include <sys/param.h>
46#include <sys/time.h>
47#include <sys/file.h>
48#include <syslog.h>
49#include <unistd.h>
50#include <stdio.h>
51#include <stdlib.h>
52#include <string.h>
53#include <locale.h>
54#include <ctype.h>
55
56time_t tval;
57int retval, nflag;
58
59main(argc, argv)
60	int argc;
61	char **argv;
62{
63	extern int optind;
64	extern char *optarg;
65	struct timezone tz;
66	int ch, rflag;
67	char *format, buf[1024];
68
69	setlocale(LC_ALL, "");
70
71	tz.tz_dsttime = tz.tz_minuteswest = 0;
72	rflag = 0;
73	while ((ch = getopt(argc, argv, "d:nr:ut:")) != -1)
74		switch((char)ch) {
75		case 'd':		/* daylight savings time */
76			tz.tz_dsttime = atoi(optarg) ? 1 : 0;
77			break;
78		case 'n':		/* don't set network */
79			nflag = 1;
80			break;
81		case 'r':		/* user specified seconds */
82			rflag = 1;
83			tval = atol(optarg);
84			break;
85		case 'u':		/* do everything in GMT */
86			(void)setenv("TZ", "GMT0", 1);
87			break;
88		case 't':		/* minutes west of GMT */
89					/* error check; don't allow "PST" */
90			if (isdigit(*optarg)) {
91				tz.tz_minuteswest = atoi(optarg);
92				break;
93			}
94			/* FALLTHROUGH */
95		default:
96			usage();
97		}
98	argc -= optind;
99	argv += optind;
100
101	/*
102	 * If -d or -t, set the timezone or daylight savings time; this
103	 * doesn't belong here, there kernel should not know about either.
104	 */
105	if ((tz.tz_minuteswest || tz.tz_dsttime) &&
106	    settimeofday((struct timeval *)NULL, &tz)) {
107		perror("date: settimeofday");
108		exit(1);
109	}
110
111	if (!rflag && time(&tval) == -1) {
112		perror("date: time");
113		exit(1);
114	}
115
116	format = "%a %b %e %H:%M:%S %Z %Y";
117
118	/* allow the operands in any order */
119	if (*argv && **argv == '+') {
120		format = *argv + 1;
121		++argv;
122	}
123
124	if (*argv) {
125		setthetime(*argv);
126		++argv;
127	}
128
129	if (*argv && **argv == '+')
130		format = *argv + 1;
131
132	(void)strftime(buf, sizeof(buf), format, localtime(&tval));
133	(void)printf("%s\n", buf);
134	exit(retval);
135}
136
137#define	ATOI2(ar)	((ar)[0] - '0') * 10 + ((ar)[1] - '0'); (ar) += 2;
138setthetime(p)
139	register char *p;
140{
141	register struct tm *lt;
142	struct timeval tv;
143	int dot;
144	char *t;
145
146	for (t = p, dot = 0; *t; ++t)
147		if (!isdigit(*t) && (*t != '.' || dot++))
148			badformat();
149
150	lt = localtime(&tval);
151
152	if (t = index(p, '.')) {		/* .ss */
153		*t++ = '\0';
154		lt->tm_sec = ATOI2(t);
155		if (lt->tm_sec > 61)
156			badformat();
157	} else
158		lt->tm_sec = 0;
159
160	for (t = p; *t; ++t)
161		if (!isdigit(*t))
162			badformat();
163
164	switch (strlen(p)) {
165	case 10:				/* yy */
166		lt->tm_year = ATOI2(p);
167		if (lt->tm_year < 69)		/* hack for 2000 ;-} */
168			lt->tm_year += 100;
169		/* FALLTHROUGH */
170	case 8:					/* mm */
171		lt->tm_mon = ATOI2(p);
172		if (lt->tm_mon > 12)
173			badformat();
174		--lt->tm_mon;			/* time struct is 0 - 11 */
175		/* FALLTHROUGH */
176	case 6:					/* dd */
177		lt->tm_mday = ATOI2(p);
178		if (lt->tm_mday > 31)
179			badformat();
180		/* FALLTHROUGH */
181	case 4:					/* hh */
182		lt->tm_hour = ATOI2(p);
183		if (lt->tm_hour > 23)
184			badformat();
185		/* FALLTHROUGH */
186	case 2:					/* mm */
187		lt->tm_min = ATOI2(p);
188		if (lt->tm_min > 59)
189			badformat();
190		break;
191	default:
192		badformat();
193	}
194
195	/* convert broken-down time to GMT clock time */
196	if ((tval = mktime(lt)) == -1)
197		badformat();
198
199	if (!(p = getlogin()))			/* single-user or no tty */
200		p = "root";
201	syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
202
203	/* set the time */
204	if (nflag || netsettime(tval)) {
205		logwtmp("|", "date", "");
206		tv.tv_sec = tval;
207		tv.tv_usec = 0;
208		if (settimeofday(&tv, (struct timezone *)NULL)) {
209			perror("date: settimeofday");
210			exit(1);
211		}
212		logwtmp("{", "date", "");
213	}
214}
215
216badformat()
217{
218	(void)fprintf(stderr, "date: illegal time format.\n");
219	usage();
220}
221
222usage()
223{
224	(void)fprintf(stderr,
225	    "usage: date [-nu] [-d dst] [-r seconds] [-t west] [+format]\n");
226	(void)fprintf(stderr, "            [yy[mm[dd[hh]]]]mm[.ss]]\n");
227	exit(1);
228}
229