xref: /openbsd/bin/date/date.c (revision 17df1aa7)
1 /*	$OpenBSD: date.c,v 1.33 2010/03/31 17:51:21 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 #include "extern.h"
50 
51 extern	char *__progname;
52 
53 time_t tval;
54 int retval, jflag, nflag;
55 int slidetime;
56 
57 static void setthetime(char *);
58 static void badformat(void);
59 static void usage(void);
60 
61 int
62 main(int argc, char *argv[])
63 {
64 	struct timezone tz;
65 	int ch, rflag;
66 	char *format, buf[1024];
67 
68 	setlocale(LC_ALL, "");
69 
70 	tz.tz_dsttime = tz.tz_minuteswest = 0;
71 	rflag = 0;
72 	while ((ch = getopt(argc, argv, "ad:jnr:ut:")) != -1)
73 		switch((char)ch) {
74 		case 'd':		/* daylight saving time */
75 			tz.tz_dsttime = atoi(optarg) ? 1 : 0;
76 			break;
77 		case 'a':
78 			slidetime++;
79 			break;
80 		case 'j':		/* don't set */
81 			jflag = 1;
82 			break;
83 		case 'n':		/* don't set network */
84 			nflag = 1;
85 			break;
86 		case 'r':		/* user specified seconds */
87 			rflag = 1;
88 			tval = atol(optarg);
89 			break;
90 		case 'u':		/* do everything in UTC */
91 			if (setenv("TZ", "UTC", 1) == -1)
92 				err(1, "cannot unsetenv TZ");
93 			break;
94 		case 't':		/* minutes west of GMT */
95 					/* error check; don't allow "PST" */
96 			if (isdigit(*optarg)) {
97 				tz.tz_minuteswest = atoi(optarg);
98 				break;
99 			}
100 			/* FALLTHROUGH */
101 		default:
102 			usage();
103 		}
104 	argc -= optind;
105 	argv += optind;
106 
107 	/*
108 	 * If -d or -t, set the timezone or daylight saving time; this
109 	 * doesn't belong here, the kernel should not know about either.
110 	 */
111 	if ((tz.tz_minuteswest || tz.tz_dsttime) &&
112 	    settimeofday(NULL, &tz))
113 		err(1, "settimeofday");
114 
115 	if (!rflag && time(&tval) == -1)
116 		err(1, "time");
117 
118 	format = "%a %b %e %H:%M:%S %Z %Y";
119 
120 	/* allow the operands in any order */
121 	if (*argv && **argv == '+') {
122 		format = *argv + 1;
123 		++argv;
124 	}
125 
126 	if (*argv) {
127 		setthetime(*argv);
128 		++argv;
129 	}
130 
131 	if (*argv && **argv == '+')
132 		format = *argv + 1;
133 
134 	(void)strftime(buf, sizeof(buf), format, localtime(&tval));
135 	(void)printf("%s\n", buf);
136 	exit(retval);
137 }
138 
139 #define	ATOI2(ar)	((ar) += 2, ((ar)[-2] - '0') * 10 + ((ar)[-1] - '0'))
140 void
141 setthetime(char *p)
142 {
143 	struct tm *lt;
144 	struct timeval tv;
145 	char *dot, *t;
146 	int yearset = 0;
147 
148 	for (t = p, dot = NULL; *t; ++t) {
149 		if (isdigit(*t))
150 			continue;
151 		if (*t == '.' && dot == NULL) {
152 			dot = t;
153 			continue;
154 		}
155 		badformat();
156 	}
157 
158 	lt = localtime(&tval);
159 
160 	lt->tm_isdst = -1;			/* correct for DST */
161 
162 	if (dot != NULL) {			/* .SS */
163 		*dot++ = '\0';
164 		if (strlen(dot) != 2)
165 			badformat();
166 		lt->tm_sec = ATOI2(dot);
167 		if (lt->tm_sec > 61)
168 			badformat();
169 	} else
170 		lt->tm_sec = 0;
171 
172 	switch (strlen(p)) {
173 	case 12:				/* cc */
174 		lt->tm_year = ATOI2(p) * 100 - TM_YEAR_BASE;
175 		yearset = 1;
176 		/* FALLTHROUGH */
177 	case 10:				/* yy */
178 		if (!yearset) {
179 			/* mask out current year, leaving only century */
180 			lt->tm_year = ((lt->tm_year / 100) * 100);
181 		}
182 		lt->tm_year += ATOI2(p);
183 		/* FALLTHROUGH */
184 	case 8:					/* mm */
185 		lt->tm_mon = ATOI2(p);
186 		if ((lt->tm_mon > 12) || !lt->tm_mon)
187 			badformat();
188 		--lt->tm_mon;			/* time struct is 0 - 11 */
189 		/* FALLTHROUGH */
190 	case 6:					/* dd */
191 		lt->tm_mday = ATOI2(p);
192 		if ((lt->tm_mday > 31) || !lt->tm_mday)
193 			badformat();
194 		/* FALLTHROUGH */
195 	case 4:					/* HH */
196 		lt->tm_hour = ATOI2(p);
197 		if (lt->tm_hour > 23)
198 			badformat();
199 		/* FALLTHROUGH */
200 	case 2:					/* MM */
201 		lt->tm_min = ATOI2(p);
202 		if (lt->tm_min > 59)
203 			badformat();
204 		break;
205 	default:
206 		badformat();
207 	}
208 
209 	/* convert broken-down time to UTC clock time */
210 	if ((tval = mktime(lt)) < 0)
211 		errx(1, "specified date is outside allowed range");
212 
213 	if (jflag)
214 		return;
215 
216 	/* set the time */
217 	if (nflag || netsettime(tval)) {
218 		if (slidetime) {
219 			struct timeval tv_current;
220 
221 			if (gettimeofday(&tv_current, NULL) == -1)
222 				err(1, "Could not get local time of day");
223 
224 			tv.tv_sec = tval - tv_current.tv_sec;
225 			tv.tv_usec = 0;
226 			if (adjtime(&tv, NULL) == -1)
227 				errx(1, "adjtime");
228 		} else {
229 #ifndef SMALL
230 			logwtmp("|", "date", "");
231 #endif
232 			tv.tv_sec = tval;
233 			tv.tv_usec = 0;
234 			if (settimeofday(&tv, NULL))
235 				err(1, "settimeofday");
236 #ifndef SMALL
237 			logwtmp("{", "date", "");
238 #endif
239 		}
240 	}
241 
242 	if ((p = getlogin()) == NULL)
243 		p = "???";
244 	syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
245 }
246 
247 #ifdef SMALL
248 int
249 netsettime(tval)
250 {
251 	return (2);
252 }
253 #endif
254 
255 static void
256 badformat(void)
257 {
258 	warnx("illegal time format");
259 	usage();
260 }
261 
262 static void
263 usage(void)
264 {
265 	(void)fprintf(stderr,
266 	    "usage: %s [-ajnu] [-d dst] [-r seconds] [-t minutes_west] [+format]\n",
267 	     __progname);
268 	(void)fprintf(stderr,
269 	    "%-*s[[[[[[cc]yy]mm]dd]HH]MM[.SS]]\n", (int)strlen(__progname) + 8, "");
270 	exit(1);
271 }
272