xref: /freebsd/bin/date/date.c (revision 9336e0699bda8a301cd2bfa37106b6ec5e32012e)
1 /*-
2  * Copyright (c) 1985, 1987, 1988, 1993
3  *	The Regents of the University of California.  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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #ifndef lint
31 static char const copyright[] =
32 "@(#) Copyright (c) 1985, 1987, 1988, 1993\n\
33 	The Regents of the University of California.  All rights reserved.\n";
34 #endif /* not lint */
35 
36 #if 0
37 #ifndef lint
38 static char sccsid[] = "@(#)date.c	8.2 (Berkeley) 4/28/95";
39 #endif /* not lint */
40 #endif
41 
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
44 
45 #include <sys/param.h>
46 #include <sys/time.h>
47 
48 #include <ctype.h>
49 #include <err.h>
50 #include <locale.h>
51 #include <libutil.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <syslog.h>
56 #include <unistd.h>
57 
58 #include "extern.h"
59 #include "vary.h"
60 
61 #ifndef	TM_YEAR_BASE
62 #define	TM_YEAR_BASE	1900
63 #endif
64 
65 static time_t tval;
66 int retval;
67 
68 static void setthetime(const char *, const char *, int, int);
69 static void badformat(void);
70 static void usage(void);
71 
72 int
73 main(int argc, char *argv[])
74 {
75 	struct timezone tz;
76 	int ch, rflag;
77 	int jflag, nflag;
78 	const char *format;
79 	char buf[1024];
80 	char *endptr, *fmt;
81 	char *tmp;
82 	int set_timezone;
83 	struct vary *v;
84 	const struct vary *badv;
85 	struct tm lt;
86 
87 	v = NULL;
88 	fmt = NULL;
89 	(void) setlocale(LC_TIME, "");
90 	tz.tz_dsttime = tz.tz_minuteswest = 0;
91 	rflag = 0;
92 	jflag = nflag = 0;
93 	set_timezone = 0;
94 	while ((ch = getopt(argc, argv, "d:f:jnr:t:uv:")) != -1)
95 		switch((char)ch) {
96 		case 'd':		/* daylight savings time */
97 			tz.tz_dsttime = strtol(optarg, &endptr, 10) ? 1 : 0;
98 			if (endptr == optarg || *endptr != '\0')
99 				usage();
100 			set_timezone = 1;
101 			break;
102 		case 'f':
103 			fmt = optarg;
104 			break;
105 		case 'j':
106 			jflag = 1;	/* don't set time */
107 			break;
108 		case 'n':		/* don't set network */
109 			nflag = 1;
110 			break;
111 		case 'r':		/* user specified seconds */
112 			rflag = 1;
113 			tval = strtoq(optarg, &tmp, 0);
114 			if (*tmp != 0)
115 				usage();
116 			break;
117 		case 't':		/* minutes west of UTC */
118 					/* error check; don't allow "PST" */
119 			tz.tz_minuteswest = strtol(optarg, &endptr, 10);
120 			if (endptr == optarg || *endptr != '\0')
121 				usage();
122 			set_timezone = 1;
123 			break;
124 		case 'u':		/* do everything in UTC */
125 			(void)setenv("TZ", "UTC0", 1);
126 			break;
127 		case 'v':
128 			v = vary_append(v, optarg);
129 			break;
130 		default:
131 			usage();
132 		}
133 	argc -= optind;
134 	argv += optind;
135 
136 	/*
137 	 * If -d or -t, set the timezone or daylight savings time; this
138 	 * doesn't belong here; the kernel should not know about either.
139 	 */
140 	if (set_timezone && settimeofday((struct timeval *)NULL, &tz))
141 		err(1, "settimeofday (timezone)");
142 
143 	if (!rflag && time(&tval) == -1)
144 		err(1, "time");
145 
146 	format = "%+";
147 
148 	/* allow the operands in any order */
149 	if (*argv && **argv == '+') {
150 		format = *argv + 1;
151 		++argv;
152 	}
153 
154 	if (*argv) {
155 		setthetime(fmt, *argv, jflag, nflag);
156 		++argv;
157 	} else if (fmt != NULL)
158 		usage();
159 
160 	if (*argv && **argv == '+')
161 		format = *argv + 1;
162 
163 	lt = *localtime(&tval);
164 	badv = vary_apply(v, &lt);
165 	if (badv) {
166 		fprintf(stderr, "%s: Cannot apply date adjustment\n",
167 			badv->arg);
168 		vary_destroy(v);
169 		usage();
170 	}
171 	vary_destroy(v);
172 	(void)strftime(buf, sizeof(buf), format, &lt);
173 	(void)printf("%s\n", buf);
174 	if (fflush(stdout))
175 		err(1, "stdout");
176 	exit(retval);
177 }
178 
179 #define	ATOI2(s)	((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))
180 
181 static void
182 setthetime(const char *fmt, const char *p, int jflag, int nflag)
183 {
184 	struct tm *lt;
185 	struct timeval tv;
186 	const char *dot, *t;
187 	int century;
188 
189 	if (fmt != NULL) {
190 		lt = localtime(&tval);
191 		t = strptime(p, fmt, lt);
192 		if (t == NULL) {
193 			fprintf(stderr, "Failed conversion of ``%s''"
194 				" using format ``%s''\n", p, fmt);
195 			badformat();
196 		} else if (*t != '\0')
197 			fprintf(stderr, "Warning: Ignoring %ld extraneous"
198 				" characters in date string (%s)\n",
199 				(long) strlen(t), t);
200 	} else {
201 		for (t = p, dot = NULL; *t; ++t) {
202 			if (isdigit(*t))
203 				continue;
204 			if (*t == '.' && dot == NULL) {
205 				dot = t;
206 				continue;
207 			}
208 			badformat();
209 		}
210 
211 		lt = localtime(&tval);
212 
213 		if (dot != NULL) {			/* .ss */
214 			dot++; /* *dot++ = '\0'; */
215 			if (strlen(dot) != 2)
216 				badformat();
217 			lt->tm_sec = ATOI2(dot);
218 			if (lt->tm_sec > 61)
219 				badformat();
220 		} else
221 			lt->tm_sec = 0;
222 
223 		century = 0;
224 		/* if p has a ".ss" field then let's pretend it's not there */
225 		switch (strlen(p) - ((dot != NULL) ? 3 : 0)) {
226 		case 12:				/* cc */
227 			lt->tm_year = ATOI2(p) * 100 - TM_YEAR_BASE;
228 			century = 1;
229 			/* FALLTHROUGH */
230 		case 10:				/* yy */
231 			if (century)
232 				lt->tm_year += ATOI2(p);
233 			else {
234 				lt->tm_year = ATOI2(p);
235 				if (lt->tm_year < 69)	/* hack for 2000 ;-} */
236 					lt->tm_year += 2000 - TM_YEAR_BASE;
237 				else
238 					lt->tm_year += 1900 - TM_YEAR_BASE;
239 			}
240 			/* FALLTHROUGH */
241 		case 8:					/* mm */
242 			lt->tm_mon = ATOI2(p);
243 			if (lt->tm_mon > 12)
244 				badformat();
245 			--lt->tm_mon;		/* time struct is 0 - 11 */
246 			/* FALLTHROUGH */
247 		case 6:					/* dd */
248 			lt->tm_mday = ATOI2(p);
249 			if (lt->tm_mday > 31)
250 				badformat();
251 			/* FALLTHROUGH */
252 		case 4:					/* HH */
253 			lt->tm_hour = ATOI2(p);
254 			if (lt->tm_hour > 23)
255 				badformat();
256 			/* FALLTHROUGH */
257 		case 2:					/* MM */
258 			lt->tm_min = ATOI2(p);
259 			if (lt->tm_min > 59)
260 				badformat();
261 			break;
262 		default:
263 			badformat();
264 		}
265 	}
266 
267 	/* Let mktime() decide whether summer time is in effect. */
268 	lt->tm_isdst = -1;
269 
270 	/* convert broken-down time to GMT clock time */
271 	if ((tval = mktime(lt)) == -1)
272 		errx(1, "nonexistent time");
273 
274 	if (!jflag) {
275 		/* set the time */
276 		if (nflag || netsettime(tval)) {
277 			logwtmp("|", "date", "");
278 			tv.tv_sec = tval;
279 			tv.tv_usec = 0;
280 			if (settimeofday(&tv, (struct timezone *)NULL))
281 				err(1, "settimeofday (timeval)");
282 			logwtmp("{", "date", "");
283 		}
284 
285 		if ((p = getlogin()) == NULL)
286 			p = "???";
287 		syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
288 	}
289 }
290 
291 static void
292 badformat(void)
293 {
294 	warnx("illegal time format");
295 	usage();
296 }
297 
298 static void
299 usage(void)
300 {
301 	(void)fprintf(stderr, "%s\n%s\n",
302 	    "usage: date [-jnu] [-d dst] [-r seconds] [-t west] "
303 	    "[-v[+|-]val[ymwdHMS]] ... ",
304 	    "            "
305 	    "[-f fmt date | [[[[[cc]yy]mm]dd]HH]MM[.ss]] [+format]");
306 	exit(1);
307 }
308