xref: /openbsd-src/bin/date/date.c (revision d13be5d47e4149db2549a9828e244d59dbc43f15)
1 /*	$OpenBSD: date.c,v 1.37 2011/07/08 18:07:16 deraadt Exp $	*/
2 /*	$NetBSD: date.c,v 1.11 1995/09/07 06:21:05 jtc Exp $	*/
3 
4 /*
5  * Copyright (c) 1985, 1987, 1988, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <sys/param.h>
34 #include <sys/time.h>
35 
36 #include <ctype.h>
37 #include <err.h>
38 #include <fcntl.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <locale.h>
43 #include <syslog.h>
44 #include <time.h>
45 #include <tzfile.h>
46 #include <unistd.h>
47 #include <util.h>
48 
49 extern	char *__progname;
50 
51 time_t tval;
52 int retval, jflag;
53 int slidetime;
54 
55 static void setthetime(char *);
56 static void badformat(void);
57 static void usage(void);
58 
59 int
60 main(int argc, char *argv[])
61 {
62 	struct timezone tz;
63 	int ch, rflag;
64 	char *format, buf[1024], *outzone = NULL;
65 
66 	setlocale(LC_ALL, "");
67 
68 	tz.tz_dsttime = tz.tz_minuteswest = 0;
69 	rflag = 0;
70 	while ((ch = getopt(argc, argv, "ad:jr:ut:z:")) != -1)
71 		switch((char)ch) {
72 		case 'd':		/* daylight saving time */
73 			tz.tz_dsttime = atoi(optarg) ? 1 : 0;
74 			break;
75 		case 'a':
76 			slidetime++;
77 			break;
78 		case 'j':		/* don't set */
79 			jflag = 1;
80 			break;
81 		case 'r':		/* user specified seconds */
82 			rflag = 1;
83 			tval = atol(optarg);
84 			break;
85 		case 'u':		/* do everything in UTC */
86 			if (setenv("TZ", "UTC", 1) == -1)
87 				err(1, "cannot unsetenv TZ");
88 			break;
89 		case 't':		/* minutes west of GMT */
90 					/* error check; don't allow "PST" */
91 			if (isdigit(*optarg)) {
92 				tz.tz_minuteswest = atoi(optarg);
93 				break;
94 			}
95 			/* FALLTHROUGH */
96 		case 'z':
97 			outzone = optarg;
98 			break;
99 		default:
100 			usage();
101 		}
102 	argc -= optind;
103 	argv += optind;
104 
105 	/*
106 	 * If -d or -t, set the timezone or daylight saving time; this
107 	 * doesn't belong here, the kernel should not know about either.
108 	 */
109 	if ((tz.tz_minuteswest || tz.tz_dsttime) &&
110 	    settimeofday(NULL, &tz))
111 		err(1, "settimeofday");
112 
113 	if (!rflag && time(&tval) == -1)
114 		err(1, "time");
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 		argc--;
123 	}
124 
125 	if (*argv) {
126 		setthetime(*argv);
127 		argv++;
128 		argc--;
129 	}
130 
131 	if (*argv && **argv == '+') {
132 		format = *argv + 1;
133 		argc--;
134 	}
135 
136 	if (argc > 0)
137 		errx(1, "too many arguments");
138 
139 	if (outzone)
140 		setenv("TZ", outzone, 1);
141 
142 	(void)strftime(buf, sizeof(buf), format, localtime(&tval));
143 	(void)printf("%s\n", buf);
144 	exit(retval);
145 }
146 
147 #define	ATOI2(ar)	((ar) += 2, ((ar)[-2] - '0') * 10 + ((ar)[-1] - '0'))
148 void
149 setthetime(char *p)
150 {
151 	struct tm *lt;
152 	struct timeval tv;
153 	char *dot, *t;
154 	int yearset = 0;
155 
156 	for (t = p, dot = NULL; *t; ++t) {
157 		if (isdigit(*t))
158 			continue;
159 		if (*t == '.' && dot == NULL) {
160 			dot = t;
161 			continue;
162 		}
163 		badformat();
164 	}
165 
166 	lt = localtime(&tval);
167 
168 	lt->tm_isdst = -1;			/* correct for DST */
169 
170 	if (dot != NULL) {			/* .SS */
171 		*dot++ = '\0';
172 		if (strlen(dot) != 2)
173 			badformat();
174 		lt->tm_sec = ATOI2(dot);
175 		if (lt->tm_sec > 61)
176 			badformat();
177 	} else
178 		lt->tm_sec = 0;
179 
180 	switch (strlen(p)) {
181 	case 12:				/* cc */
182 		lt->tm_year = ATOI2(p) * 100 - TM_YEAR_BASE;
183 		yearset = 1;
184 		/* FALLTHROUGH */
185 	case 10:				/* yy */
186 		if (!yearset) {
187 			/* mask out current year, leaving only century */
188 			lt->tm_year = ((lt->tm_year / 100) * 100);
189 		}
190 		lt->tm_year += ATOI2(p);
191 		/* FALLTHROUGH */
192 	case 8:					/* mm */
193 		lt->tm_mon = ATOI2(p);
194 		if ((lt->tm_mon > 12) || !lt->tm_mon)
195 			badformat();
196 		--lt->tm_mon;			/* time struct is 0 - 11 */
197 		/* FALLTHROUGH */
198 	case 6:					/* dd */
199 		lt->tm_mday = ATOI2(p);
200 		if ((lt->tm_mday > 31) || !lt->tm_mday)
201 			badformat();
202 		/* FALLTHROUGH */
203 	case 4:					/* HH */
204 		lt->tm_hour = ATOI2(p);
205 		if (lt->tm_hour > 23)
206 			badformat();
207 		/* FALLTHROUGH */
208 	case 2:					/* MM */
209 		lt->tm_min = ATOI2(p);
210 		if (lt->tm_min > 59)
211 			badformat();
212 		break;
213 	default:
214 		badformat();
215 	}
216 
217 	/* convert broken-down time to UTC clock time */
218 	if ((tval = mktime(lt)) < 0)
219 		errx(1, "specified date is outside allowed range");
220 
221 	if (jflag)
222 		return;
223 
224 	/* set the time */
225 	if (slidetime) {
226 		struct timeval tv_current;
227 
228 		if (gettimeofday(&tv_current, NULL) == -1)
229 			err(1, "Could not get local time of day");
230 
231 		tv.tv_sec = tval - tv_current.tv_sec;
232 		tv.tv_usec = 0;
233 		if (adjtime(&tv, NULL) == -1)
234 			errx(1, "adjtime");
235 	} else {
236 #ifndef SMALL
237 		logwtmp("|", "date", "");
238 #endif
239 		tv.tv_sec = tval;
240 		tv.tv_usec = 0;
241 		if (settimeofday(&tv, NULL))
242 			err(1, "settimeofday");
243 #ifndef SMALL
244 		logwtmp("{", "date", "");
245 #endif
246 	}
247 
248 	if ((p = getlogin()) == NULL)
249 		p = "???";
250 	syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
251 }
252 
253 static void
254 badformat(void)
255 {
256 	warnx("illegal time format");
257 	usage();
258 }
259 
260 static void
261 usage(void)
262 {
263 	(void)fprintf(stderr,
264 	    "usage: %s [-aju] [-d dst] [-r seconds] [-t minutes_west] [-z output_zone]\n",
265 	     __progname);
266 	(void)fprintf(stderr,
267 	    "%-*s[+format] [[[[[[cc]yy]mm]dd]HH]MM[.SS]]\n", (int)strlen(__progname) + 8, "");
268 	exit(1);
269 }
270