xref: /freebsd/bin/date/date.c (revision 43d1e6ee299ad4e143d90d3ad374d1c24bd3306f)
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 "vary.h"
63 
64 #ifndef	TM_YEAR_BASE
65 #define	TM_YEAR_BASE	1900
66 #endif
67 
68 static time_t tval;
69 
70 static void badformat(void);
71 static void iso8601_usage(const char *);
72 static void multipleformats(void);
73 static void printdate(const char *);
74 static void printisodate(struct tm *);
75 static void setthetime(const char *, const char *, int);
76 static void usage(void);
77 
78 static const struct iso8601_fmt {
79 	const char *refname;
80 	const char *format_string;
81 } iso8601_fmts[] = {
82 	{ "date", "%Y-%m-%d" },
83 	{ "hours", "T%H" },
84 	{ "minutes", ":%M" },
85 	{ "seconds", ":%S" },
86 };
87 static const struct iso8601_fmt *iso8601_selected;
88 
89 static const char *rfc2822_format = "%a, %d %b %Y %T %z";
90 
91 int
92 main(int argc, char *argv[])
93 {
94 	int ch, rflag;
95 	bool Iflag, jflag, Rflag;
96 	const char *format;
97 	char buf[1024];
98 	char *fmt;
99 	char *tmp;
100 	struct vary *v;
101 	const struct vary *badv;
102 	struct tm *lt;
103 	struct stat sb;
104 	size_t i;
105 
106 	v = NULL;
107 	fmt = NULL;
108 	(void) setlocale(LC_TIME, "");
109 	rflag = 0;
110 	Iflag = jflag = Rflag = 0;
111 	while ((ch = getopt(argc, argv, "f:I::jRr:uv:")) != -1)
112 		switch((char)ch) {
113 		case 'f':
114 			fmt = optarg;
115 			break;
116 		case 'I':
117 			if (Rflag)
118 				multipleformats();
119 			Iflag = 1;
120 			if (optarg == NULL) {
121 				iso8601_selected = iso8601_fmts;
122 				break;
123 			}
124 			for (i = 0; i < nitems(iso8601_fmts); i++)
125 				if (strcmp(optarg, iso8601_fmts[i].refname) == 0)
126 					break;
127 			if (i == nitems(iso8601_fmts))
128 				iso8601_usage(optarg);
129 
130 			iso8601_selected = &iso8601_fmts[i];
131 			break;
132 		case 'j':
133 			jflag = 1;	/* don't set time */
134 			break;
135 		case 'R':		/* RFC 2822 datetime format */
136 			if (Iflag)
137 				multipleformats();
138 			Rflag = 1;
139 			break;
140 		case 'r':		/* user specified seconds */
141 			rflag = 1;
142 			tval = strtoq(optarg, &tmp, 0);
143 			if (*tmp != 0) {
144 				if (stat(optarg, &sb) == 0)
145 					tval = sb.st_mtim.tv_sec;
146 				else
147 					usage();
148 			}
149 			break;
150 		case 'u':		/* do everything in UTC */
151 			(void)setenv("TZ", "UTC0", 1);
152 			break;
153 		case 'v':
154 			v = vary_append(v, optarg);
155 			break;
156 		default:
157 			usage();
158 		}
159 	argc -= optind;
160 	argv += optind;
161 
162 	if (!rflag && time(&tval) == -1)
163 		err(1, "time");
164 
165 	format = "%+";
166 
167 	if (Rflag)
168 		format = rfc2822_format;
169 
170 	/* allow the operands in any order */
171 	if (*argv && **argv == '+') {
172 		if (Iflag)
173 			multipleformats();
174 		format = *argv + 1;
175 		++argv;
176 	}
177 
178 	if (*argv) {
179 		setthetime(fmt, *argv, jflag);
180 		++argv;
181 	} else if (fmt != NULL)
182 		usage();
183 
184 	if (*argv && **argv == '+') {
185 		if (Iflag)
186 			multipleformats();
187 		format = *argv + 1;
188 	}
189 
190 	lt = localtime(&tval);
191 	if (lt == NULL)
192 		errx(1, "invalid time");
193 	badv = vary_apply(v, lt);
194 	if (badv) {
195 		fprintf(stderr, "%s: Cannot apply date adjustment\n",
196 			badv->arg);
197 		vary_destroy(v);
198 		usage();
199 	}
200 	vary_destroy(v);
201 
202 	if (Iflag)
203 		printisodate(lt);
204 
205 	if (format == rfc2822_format)
206 		/*
207 		 * When using RFC 2822 datetime format, don't honor the
208 		 * locale.
209 		 */
210 		setlocale(LC_TIME, "C");
211 
212 	(void)strftime(buf, sizeof(buf), format, lt);
213 	printdate(buf);
214 }
215 
216 static void
217 printdate(const char *buf)
218 {
219 	(void)printf("%s\n", buf);
220 	if (fflush(stdout))
221 		err(1, "stdout");
222 	exit(EXIT_SUCCESS);
223 }
224 
225 static void
226 printisodate(struct tm *lt)
227 {
228 	const struct iso8601_fmt *it;
229 	char fmtbuf[32], buf[32], tzbuf[8];
230 
231 	fmtbuf[0] = 0;
232 	for (it = iso8601_fmts; it <= iso8601_selected; it++)
233 		strlcat(fmtbuf, it->format_string, sizeof(fmtbuf));
234 
235 	(void)strftime(buf, sizeof(buf), fmtbuf, lt);
236 
237 	if (iso8601_selected > iso8601_fmts) {
238 		(void)strftime(tzbuf, sizeof(tzbuf), "%z", lt);
239 		memmove(&tzbuf[4], &tzbuf[3], 3);
240 		tzbuf[3] = ':';
241 		strlcat(buf, tzbuf, sizeof(buf));
242 	}
243 
244 	printdate(buf);
245 }
246 
247 #define	ATOI2(s)	((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))
248 
249 static void
250 setthetime(const char *fmt, const char *p, int jflag)
251 {
252 	struct utmpx utx;
253 	struct tm *lt;
254 	struct timeval tv;
255 	const char *dot, *t;
256 	int century;
257 
258 	lt = localtime(&tval);
259 	if (lt == NULL)
260 		errx(1, "invalid time");
261 	lt->tm_isdst = -1;		/* divine correct DST */
262 
263 	if (fmt != NULL) {
264 		t = strptime(p, fmt, lt);
265 		if (t == NULL) {
266 			fprintf(stderr, "Failed conversion of ``%s''"
267 				" using format ``%s''\n", p, fmt);
268 			badformat();
269 		} else if (*t != '\0')
270 			fprintf(stderr, "Warning: Ignoring %ld extraneous"
271 				" characters in date string (%s)\n",
272 				(long) strlen(t), t);
273 	} else {
274 		for (t = p, dot = NULL; *t; ++t) {
275 			if (isdigit(*t))
276 				continue;
277 			if (*t == '.' && dot == NULL) {
278 				dot = t;
279 				continue;
280 			}
281 			badformat();
282 		}
283 
284 		if (dot != NULL) {			/* .ss */
285 			dot++; /* *dot++ = '\0'; */
286 			if (strlen(dot) != 2)
287 				badformat();
288 			lt->tm_sec = ATOI2(dot);
289 			if (lt->tm_sec > 61)
290 				badformat();
291 		} else
292 			lt->tm_sec = 0;
293 
294 		century = 0;
295 		/* if p has a ".ss" field then let's pretend it's not there */
296 		switch (strlen(p) - ((dot != NULL) ? 3 : 0)) {
297 		case 12:				/* cc */
298 			lt->tm_year = ATOI2(p) * 100 - TM_YEAR_BASE;
299 			century = 1;
300 			/* FALLTHROUGH */
301 		case 10:				/* yy */
302 			if (century)
303 				lt->tm_year += ATOI2(p);
304 			else {
305 				lt->tm_year = ATOI2(p);
306 				if (lt->tm_year < 69)	/* hack for 2000 ;-} */
307 					lt->tm_year += 2000 - TM_YEAR_BASE;
308 				else
309 					lt->tm_year += 1900 - TM_YEAR_BASE;
310 			}
311 			/* FALLTHROUGH */
312 		case 8:					/* mm */
313 			lt->tm_mon = ATOI2(p);
314 			if (lt->tm_mon > 12)
315 				badformat();
316 			--lt->tm_mon;		/* time struct is 0 - 11 */
317 			/* FALLTHROUGH */
318 		case 6:					/* dd */
319 			lt->tm_mday = ATOI2(p);
320 			if (lt->tm_mday > 31)
321 				badformat();
322 			/* FALLTHROUGH */
323 		case 4:					/* HH */
324 			lt->tm_hour = ATOI2(p);
325 			if (lt->tm_hour > 23)
326 				badformat();
327 			/* FALLTHROUGH */
328 		case 2:					/* MM */
329 			lt->tm_min = ATOI2(p);
330 			if (lt->tm_min > 59)
331 				badformat();
332 			break;
333 		default:
334 			badformat();
335 		}
336 	}
337 
338 	/* convert broken-down time to GMT clock time */
339 	if ((tval = mktime(lt)) == -1)
340 		errx(1, "nonexistent time");
341 
342 	if (!jflag) {
343 		utx.ut_type = OLD_TIME;
344 		memset(utx.ut_id, 0, sizeof(utx.ut_id));
345 		(void)gettimeofday(&utx.ut_tv, NULL);
346 		pututxline(&utx);
347 		tv.tv_sec = tval;
348 		tv.tv_usec = 0;
349 		if (settimeofday(&tv, NULL) != 0)
350 			err(1, "settimeofday (timeval)");
351 		utx.ut_type = NEW_TIME;
352 		(void)gettimeofday(&utx.ut_tv, NULL);
353 		pututxline(&utx);
354 
355 		if ((p = getlogin()) == NULL)
356 			p = "???";
357 		syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
358 	}
359 }
360 
361 static void
362 badformat(void)
363 {
364 	warnx("illegal time format");
365 	usage();
366 }
367 
368 static void
369 iso8601_usage(const char *badarg)
370 {
371 	errx(1, "invalid argument '%s' for -I", badarg);
372 }
373 
374 static void
375 multipleformats(void)
376 {
377 	errx(1, "multiple output formats specified");
378 }
379 
380 static void
381 usage(void)
382 {
383 	(void)fprintf(stderr, "%s\n%s\n%s\n",
384 	    "usage: date [-jnRu] [-r seconds|file] [-v[+|-]val[ymwdHMS]]",
385 	    "            "
386 	    "[-I[date | hours | minutes | seconds]]",
387 	    "            "
388 	    "[-f fmt date | [[[[[cc]yy]mm]dd]HH]MM[.ss]] [+format]"
389 	    );
390 	exit(1);
391 }
392