xref: /freebsd/bin/date/date.c (revision d3d381b2b194b4d24853e92eecef55f262688d1a)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1985, 1987, 1988, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef lint
33 static char const copyright[] =
34 "@(#) Copyright (c) 1985, 1987, 1988, 1993\n\
35 	The Regents of the University of California.  All rights reserved.\n";
36 #endif /* not lint */
37 
38 #if 0
39 #ifndef lint
40 static char sccsid[] = "@(#)date.c	8.2 (Berkeley) 4/28/95";
41 #endif /* not lint */
42 #endif
43 
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD$");
46 
47 #include <sys/param.h>
48 #include <sys/time.h>
49 #include <sys/stat.h>
50 
51 #include <ctype.h>
52 #include <err.h>
53 #include <locale.h>
54 #include <stdbool.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include <syslog.h>
59 #include <unistd.h>
60 #include <utmpx.h>
61 
62 #include "extern.h"
63 #include "vary.h"
64 
65 #ifndef	TM_YEAR_BASE
66 #define	TM_YEAR_BASE	1900
67 #endif
68 
69 static time_t tval;
70 int retval;
71 
72 static void badformat(void);
73 static void iso8601_usage(const char *);
74 static void multipleformats(void);
75 static void printdate(const char *);
76 static void printisodate(struct tm *);
77 static void setthetime(const char *, const char *, int, int);
78 static void usage(void);
79 
80 static const struct iso8601_fmt {
81 	const char *refname;
82 	const char *format_string;
83 } iso8601_fmts[] = {
84 	{ "date", "%Y-%m-%d" },
85 	{ "hours", "T%H" },
86 	{ "minutes", ":%M" },
87 	{ "seconds", ":%S" },
88 };
89 static const struct iso8601_fmt *iso8601_selected;
90 
91 static const char *rfc2822_format = "%a, %d %b %Y %T %z";
92 
93 int
94 main(int argc, char *argv[])
95 {
96 	struct timezone tz;
97 	int ch, rflag;
98 	bool Iflag, jflag, nflag, Rflag;
99 	const char *format;
100 	char buf[1024];
101 	char *endptr, *fmt;
102 	char *tmp;
103 	int set_timezone;
104 	struct vary *v;
105 	const struct vary *badv;
106 	struct tm *lt;
107 	struct stat sb;
108 	size_t i;
109 
110 	v = NULL;
111 	fmt = NULL;
112 	(void) setlocale(LC_TIME, "");
113 	tz.tz_dsttime = tz.tz_minuteswest = 0;
114 	rflag = 0;
115 	Iflag = jflag = nflag = Rflag = 0;
116 	set_timezone = 0;
117 	while ((ch = getopt(argc, argv, "d:f:I::jnRr:t:uv:")) != -1)
118 		switch((char)ch) {
119 		case 'd':		/* daylight savings time */
120 			tz.tz_dsttime = strtol(optarg, &endptr, 10) ? 1 : 0;
121 			if (endptr == optarg || *endptr != '\0')
122 				usage();
123 			set_timezone = 1;
124 			break;
125 		case 'f':
126 			fmt = optarg;
127 			break;
128 		case 'I':
129 			if (Rflag)
130 				multipleformats();
131 			Iflag = 1;
132 			if (optarg == NULL) {
133 				iso8601_selected = iso8601_fmts;
134 				break;
135 			}
136 			for (i = 0; i < nitems(iso8601_fmts); i++)
137 				if (strcmp(optarg, iso8601_fmts[i].refname) == 0)
138 					break;
139 			if (i == nitems(iso8601_fmts))
140 				iso8601_usage(optarg);
141 
142 			iso8601_selected = &iso8601_fmts[i];
143 			break;
144 		case 'j':
145 			jflag = 1;	/* don't set time */
146 			break;
147 		case 'n':		/* don't set network */
148 			nflag = 1;
149 			break;
150 		case 'R':		/* RFC 2822 datetime format */
151 			if (Iflag)
152 				multipleformats();
153 			Rflag = 1;
154 			break;
155 		case 'r':		/* user specified seconds */
156 			rflag = 1;
157 			tval = strtoq(optarg, &tmp, 0);
158 			if (*tmp != 0) {
159 				if (stat(optarg, &sb) == 0)
160 					tval = sb.st_mtim.tv_sec;
161 				else
162 					usage();
163 			}
164 			break;
165 		case 't':		/* minutes west of UTC */
166 					/* error check; don't allow "PST" */
167 			tz.tz_minuteswest = strtol(optarg, &endptr, 10);
168 			if (endptr == optarg || *endptr != '\0')
169 				usage();
170 			set_timezone = 1;
171 			break;
172 		case 'u':		/* do everything in UTC */
173 			(void)setenv("TZ", "UTC0", 1);
174 			break;
175 		case 'v':
176 			v = vary_append(v, optarg);
177 			break;
178 		default:
179 			usage();
180 		}
181 	argc -= optind;
182 	argv += optind;
183 
184 	/*
185 	 * If -d or -t, set the timezone or daylight savings time; this
186 	 * doesn't belong here; the kernel should not know about either.
187 	 */
188 	if (set_timezone && settimeofday(NULL, &tz) != 0)
189 		err(1, "settimeofday (timezone)");
190 
191 	if (!rflag && time(&tval) == -1)
192 		err(1, "time");
193 
194 	format = "%+";
195 
196 	if (Rflag)
197 		format = rfc2822_format;
198 
199 	/* allow the operands in any order */
200 	if (*argv && **argv == '+') {
201 		if (Iflag)
202 			multipleformats();
203 		format = *argv + 1;
204 		++argv;
205 	}
206 
207 	if (*argv) {
208 		setthetime(fmt, *argv, jflag, nflag);
209 		++argv;
210 	} else if (fmt != NULL)
211 		usage();
212 
213 	if (*argv && **argv == '+') {
214 		if (Iflag)
215 			multipleformats();
216 		format = *argv + 1;
217 	}
218 
219 	lt = localtime(&tval);
220 	if (lt == NULL)
221 		errx(1, "invalid time");
222 	badv = vary_apply(v, lt);
223 	if (badv) {
224 		fprintf(stderr, "%s: Cannot apply date adjustment\n",
225 			badv->arg);
226 		vary_destroy(v);
227 		usage();
228 	}
229 	vary_destroy(v);
230 
231 	if (Iflag)
232 		printisodate(lt);
233 
234 	if (format == rfc2822_format)
235 		/*
236 		 * When using RFC 2822 datetime format, don't honor the
237 		 * locale.
238 		 */
239 		setlocale(LC_TIME, "C");
240 
241 	(void)strftime(buf, sizeof(buf), format, lt);
242 	printdate(buf);
243 }
244 
245 static void
246 printdate(const char *buf)
247 {
248 	(void)printf("%s\n", buf);
249 	if (fflush(stdout))
250 		err(1, "stdout");
251 	exit(retval);
252 }
253 
254 static void
255 printisodate(struct tm *lt)
256 {
257 	const struct iso8601_fmt *it;
258 	char fmtbuf[32], buf[32], tzbuf[8];
259 
260 	fmtbuf[0] = 0;
261 	for (it = iso8601_fmts; it <= iso8601_selected; it++)
262 		strlcat(fmtbuf, it->format_string, sizeof(fmtbuf));
263 
264 	(void)strftime(buf, sizeof(buf), fmtbuf, lt);
265 
266 	if (iso8601_selected > iso8601_fmts) {
267 		(void)strftime(tzbuf, sizeof(tzbuf), "%z", lt);
268 		memmove(&tzbuf[4], &tzbuf[3], 3);
269 		tzbuf[3] = ':';
270 		strlcat(buf, tzbuf, sizeof(buf));
271 	}
272 
273 	printdate(buf);
274 }
275 
276 #define	ATOI2(s)	((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))
277 
278 static void
279 setthetime(const char *fmt, const char *p, int jflag, int nflag)
280 {
281 	struct utmpx utx;
282 	struct tm *lt;
283 	struct timeval tv;
284 	const char *dot, *t;
285 	int century;
286 
287 	lt = localtime(&tval);
288 	if (lt == NULL)
289 		errx(1, "invalid time");
290 	lt->tm_isdst = -1;		/* divine correct DST */
291 
292 	if (fmt != NULL) {
293 		t = strptime(p, fmt, lt);
294 		if (t == NULL) {
295 			fprintf(stderr, "Failed conversion of ``%s''"
296 				" using format ``%s''\n", p, fmt);
297 			badformat();
298 		} else if (*t != '\0')
299 			fprintf(stderr, "Warning: Ignoring %ld extraneous"
300 				" characters in date string (%s)\n",
301 				(long) strlen(t), t);
302 	} else {
303 		for (t = p, dot = NULL; *t; ++t) {
304 			if (isdigit(*t))
305 				continue;
306 			if (*t == '.' && dot == NULL) {
307 				dot = t;
308 				continue;
309 			}
310 			badformat();
311 		}
312 
313 		if (dot != NULL) {			/* .ss */
314 			dot++; /* *dot++ = '\0'; */
315 			if (strlen(dot) != 2)
316 				badformat();
317 			lt->tm_sec = ATOI2(dot);
318 			if (lt->tm_sec > 61)
319 				badformat();
320 		} else
321 			lt->tm_sec = 0;
322 
323 		century = 0;
324 		/* if p has a ".ss" field then let's pretend it's not there */
325 		switch (strlen(p) - ((dot != NULL) ? 3 : 0)) {
326 		case 12:				/* cc */
327 			lt->tm_year = ATOI2(p) * 100 - TM_YEAR_BASE;
328 			century = 1;
329 			/* FALLTHROUGH */
330 		case 10:				/* yy */
331 			if (century)
332 				lt->tm_year += ATOI2(p);
333 			else {
334 				lt->tm_year = ATOI2(p);
335 				if (lt->tm_year < 69)	/* hack for 2000 ;-} */
336 					lt->tm_year += 2000 - TM_YEAR_BASE;
337 				else
338 					lt->tm_year += 1900 - TM_YEAR_BASE;
339 			}
340 			/* FALLTHROUGH */
341 		case 8:					/* mm */
342 			lt->tm_mon = ATOI2(p);
343 			if (lt->tm_mon > 12)
344 				badformat();
345 			--lt->tm_mon;		/* time struct is 0 - 11 */
346 			/* FALLTHROUGH */
347 		case 6:					/* dd */
348 			lt->tm_mday = ATOI2(p);
349 			if (lt->tm_mday > 31)
350 				badformat();
351 			/* FALLTHROUGH */
352 		case 4:					/* HH */
353 			lt->tm_hour = ATOI2(p);
354 			if (lt->tm_hour > 23)
355 				badformat();
356 			/* FALLTHROUGH */
357 		case 2:					/* MM */
358 			lt->tm_min = ATOI2(p);
359 			if (lt->tm_min > 59)
360 				badformat();
361 			break;
362 		default:
363 			badformat();
364 		}
365 	}
366 
367 	/* convert broken-down time to GMT clock time */
368 	if ((tval = mktime(lt)) == -1)
369 		errx(1, "nonexistent time");
370 
371 	if (!jflag) {
372 		/* set the time */
373 		if (nflag || netsettime(tval)) {
374 			utx.ut_type = OLD_TIME;
375 			memset(utx.ut_id, 0, sizeof(utx.ut_id));
376 			(void)gettimeofday(&utx.ut_tv, NULL);
377 			pututxline(&utx);
378 			tv.tv_sec = tval;
379 			tv.tv_usec = 0;
380 			if (settimeofday(&tv, NULL) != 0)
381 				err(1, "settimeofday (timeval)");
382 			utx.ut_type = NEW_TIME;
383 			(void)gettimeofday(&utx.ut_tv, NULL);
384 			pututxline(&utx);
385 		}
386 
387 		if ((p = getlogin()) == NULL)
388 			p = "???";
389 		syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
390 	}
391 }
392 
393 static void
394 badformat(void)
395 {
396 	warnx("illegal time format");
397 	usage();
398 }
399 
400 static void
401 iso8601_usage(const char *badarg)
402 {
403 	errx(1, "invalid argument '%s' for -I", badarg);
404 }
405 
406 static void
407 multipleformats(void)
408 {
409 	errx(1, "multiple output formats specified");
410 }
411 
412 static void
413 usage(void)
414 {
415 	(void)fprintf(stderr, "%s\n%s\n%s\n",
416 	    "usage: date [-jnRu] [-d dst] [-r seconds|file] [-t west] "
417 	    "[-v[+|-]val[ymwdHMS]]",
418 	    "            "
419 	    "[-I[date | hours | minutes | seconds]]",
420 	    "            "
421 	    "[-f fmt date | [[[[[cc]yy]mm]dd]HH]MM[.ss]] [+format]"
422 	    );
423 	exit(1);
424 }
425