date.c revision 1.6 
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 1.6 1993/08/16 23:08:52 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 <ctype.h>
54
55time_t tval;
56int retval, nflag;
57
58main(argc, argv)
59	int argc;
60	char **argv;
61{
62	extern int optind;
63	extern char *optarg;
64	struct timezone tz;
65	int ch, rflag;
66	char *format, buf[1024];
67
68	tz.tz_dsttime = tz.tz_minuteswest = 0;
69	rflag = 0;
70	while ((ch = getopt(argc, argv, "d:nr:ut:")) != EOF)
71		switch((char)ch) {
72		case 'd':		/* daylight savings time */
73			tz.tz_dsttime = atoi(optarg) ? 1 : 0;
74			break;
75		case 'n':		/* don't set network */
76			nflag = 1;
77			break;
78		case 'r':		/* user specified seconds */
79			rflag = 1;
80			tval = atol(optarg);
81			break;
82		case 'u':		/* do everything in GMT */
83			(void)setenv("TZ", "GMT0", 1);
84			break;
85		case 't':		/* minutes west of GMT */
86					/* error check; don't allow "PST" */
87			if (isdigit(*optarg)) {
88				tz.tz_minuteswest = atoi(optarg);
89				break;
90			}
91			/* FALLTHROUGH */
92		default:
93			usage();
94		}
95	argc -= optind;
96	argv += optind;
97
98	/*
99	 * If -d or -t, set the timezone or daylight savings time; this
100	 * doesn't belong here, there kernel should not know about either.
101	 */
102	if ((tz.tz_minuteswest || tz.tz_dsttime) &&
103	    settimeofday((struct timeval *)NULL, &tz)) {
104		perror("date: settimeofday");
105		exit(1);
106	}
107
108	if (!rflag && time(&tval) == -1) {
109		perror("date: time");
110		exit(1);
111	}
112
113	format = "%a %b %e %H:%M:%S %Z %Y";
114
115	/* allow the operands in any order */
116	if (*argv && **argv == '+') {
117		format = *argv + 1;
118		++argv;
119	}
120
121	if (*argv) {
122		setthetime(*argv);
123		++argv;
124	}
125
126	if (*argv && **argv == '+')
127		format = *argv + 1;
128
129	(void)strftime(buf, sizeof(buf), format, localtime(&tval));
130	(void)printf("%s\n", buf);
131	exit(retval);
132}
133
134#define	ATOI2(ar)	((ar)[0] - '0') * 10 + ((ar)[1] - '0'); (ar) += 2;
135setthetime(p)
136	register char *p;
137{
138	register struct tm *lt;
139	struct timeval tv;
140	int dot;
141	char *t;
142
143	for (t = p, dot = 0; *t; ++t)
144		if (!isdigit(*t) && (*t != '.' || dot++))
145			badformat();
146
147	lt = localtime(&tval);
148
149	if (t = index(p, '.')) {		/* .ss */
150		*t++ = '\0';
151		lt->tm_sec = ATOI2(t);
152		if (lt->tm_sec > 61)
153			badformat();
154	} else
155		lt->tm_sec = 0;
156
157	for (t = p; *t; ++t)
158		if (!isdigit(*t))
159			badformat();
160
161	switch (strlen(p)) {
162	case 10:				/* yy */
163		lt->tm_year = ATOI2(p);
164		if (lt->tm_year < 69)		/* hack for 2000 ;-} */
165			lt->tm_year += 100;
166		/* FALLTHROUGH */
167	case 8:					/* mm */
168		lt->tm_mon = ATOI2(p);
169		if (lt->tm_mon > 12)
170			badformat();
171		--lt->tm_mon;			/* time struct is 0 - 11 */
172		/* FALLTHROUGH */
173	case 6:					/* dd */
174		lt->tm_mday = ATOI2(p);
175		if (lt->tm_mday > 31)
176			badformat();
177		/* FALLTHROUGH */
178	case 4:					/* hh */
179		lt->tm_hour = ATOI2(p);
180		if (lt->tm_hour > 23)
181			badformat();
182		/* FALLTHROUGH */
183	case 2:					/* mm */
184		lt->tm_min = ATOI2(p);
185		if (lt->tm_min > 59)
186			badformat();
187		break;
188	default:
189		badformat();
190	}
191
192	/* convert broken-down time to GMT clock time */
193	if ((tval = mktime(lt)) == -1)
194		badformat();
195
196	if (!(p = getlogin()))			/* single-user or no tty */
197		p = "root";
198	syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
199
200	/* set the time */
201	if (nflag || netsettime(tval)) {
202		logwtmp("|", "date", "");
203		tv.tv_sec = tval;
204		tv.tv_usec = 0;
205		if (settimeofday(&tv, (struct timezone *)NULL)) {
206			perror("date: settimeofday");
207			exit(1);
208		}
209		logwtmp("{", "date", "");
210	}
211}
212
213badformat()
214{
215	(void)fprintf(stderr, "date: illegal time format.\n");
216	usage();
217}
218
219usage()
220{
221	(void)fprintf(stderr,
222	    "usage: date [-nu] [-d dst] [-r seconds] [-t west] [+format]\n");
223	(void)fprintf(stderr, "            [yy[mm[dd[hh]]]]mm[.ss]]\n");
224	exit(1);
225}
226