xref: /freebsd/bin/date/date.c (revision 8881d206f4e68b564c2c5f50fc717086fc3e827a)
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::jnRr: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 'n':
136 			break;
137 		case 'R':		/* RFC 2822 datetime format */
138 			if (Iflag)
139 				multipleformats();
140 			Rflag = 1;
141 			break;
142 		case 'r':		/* user specified seconds */
143 			rflag = 1;
144 			tval = strtoq(optarg, &tmp, 0);
145 			if (*tmp != 0) {
146 				if (stat(optarg, &sb) == 0)
147 					tval = sb.st_mtim.tv_sec;
148 				else
149 					usage();
150 			}
151 			break;
152 		case 'u':		/* do everything in UTC */
153 			(void)setenv("TZ", "UTC0", 1);
154 			break;
155 		case 'v':
156 			v = vary_append(v, optarg);
157 			break;
158 		default:
159 			usage();
160 		}
161 	argc -= optind;
162 	argv += optind;
163 
164 	if (!rflag && time(&tval) == -1)
165 		err(1, "time");
166 
167 	format = "%+";
168 
169 	if (Rflag)
170 		format = rfc2822_format;
171 
172 	/* allow the operands in any order */
173 	if (*argv && **argv == '+') {
174 		if (Iflag)
175 			multipleformats();
176 		format = *argv + 1;
177 		++argv;
178 	}
179 
180 	if (*argv) {
181 		setthetime(fmt, *argv, jflag);
182 		++argv;
183 	} else if (fmt != NULL)
184 		usage();
185 
186 	if (*argv && **argv == '+') {
187 		if (Iflag)
188 			multipleformats();
189 		format = *argv + 1;
190 	}
191 
192 	lt = localtime(&tval);
193 	if (lt == NULL)
194 		errx(1, "invalid time");
195 	badv = vary_apply(v, lt);
196 	if (badv) {
197 		fprintf(stderr, "%s: Cannot apply date adjustment\n",
198 			badv->arg);
199 		vary_destroy(v);
200 		usage();
201 	}
202 	vary_destroy(v);
203 
204 	if (Iflag)
205 		printisodate(lt);
206 
207 	if (format == rfc2822_format)
208 		/*
209 		 * When using RFC 2822 datetime format, don't honor the
210 		 * locale.
211 		 */
212 		setlocale(LC_TIME, "C");
213 
214 	(void)strftime(buf, sizeof(buf), format, lt);
215 	printdate(buf);
216 }
217 
218 static void
219 printdate(const char *buf)
220 {
221 	(void)printf("%s\n", buf);
222 	if (fflush(stdout))
223 		err(1, "stdout");
224 	exit(EXIT_SUCCESS);
225 }
226 
227 static void
228 printisodate(struct tm *lt)
229 {
230 	const struct iso8601_fmt *it;
231 	char fmtbuf[32], buf[32], tzbuf[8];
232 
233 	fmtbuf[0] = 0;
234 	for (it = iso8601_fmts; it <= iso8601_selected; it++)
235 		strlcat(fmtbuf, it->format_string, sizeof(fmtbuf));
236 
237 	(void)strftime(buf, sizeof(buf), fmtbuf, lt);
238 
239 	if (iso8601_selected > iso8601_fmts) {
240 		(void)strftime(tzbuf, sizeof(tzbuf), "%z", lt);
241 		memmove(&tzbuf[4], &tzbuf[3], 3);
242 		tzbuf[3] = ':';
243 		strlcat(buf, tzbuf, sizeof(buf));
244 	}
245 
246 	printdate(buf);
247 }
248 
249 #define	ATOI2(s)	((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))
250 
251 static void
252 setthetime(const char *fmt, const char *p, int jflag)
253 {
254 	struct utmpx utx;
255 	struct tm *lt;
256 	struct timeval tv;
257 	const char *dot, *t;
258 	int century;
259 
260 	lt = localtime(&tval);
261 	if (lt == NULL)
262 		errx(1, "invalid time");
263 	lt->tm_isdst = -1;		/* divine correct DST */
264 
265 	if (fmt != NULL) {
266 		t = strptime(p, fmt, lt);
267 		if (t == NULL) {
268 			fprintf(stderr, "Failed conversion of ``%s''"
269 				" using format ``%s''\n", p, fmt);
270 			badformat();
271 		} else if (*t != '\0')
272 			fprintf(stderr, "Warning: Ignoring %ld extraneous"
273 				" characters in date string (%s)\n",
274 				(long) strlen(t), t);
275 	} else {
276 		for (t = p, dot = NULL; *t; ++t) {
277 			if (isdigit(*t))
278 				continue;
279 			if (*t == '.' && dot == NULL) {
280 				dot = t;
281 				continue;
282 			}
283 			badformat();
284 		}
285 
286 		if (dot != NULL) {			/* .ss */
287 			dot++; /* *dot++ = '\0'; */
288 			if (strlen(dot) != 2)
289 				badformat();
290 			lt->tm_sec = ATOI2(dot);
291 			if (lt->tm_sec > 61)
292 				badformat();
293 		} else
294 			lt->tm_sec = 0;
295 
296 		century = 0;
297 		/* if p has a ".ss" field then let's pretend it's not there */
298 		switch (strlen(p) - ((dot != NULL) ? 3 : 0)) {
299 		case 12:				/* cc */
300 			lt->tm_year = ATOI2(p) * 100 - TM_YEAR_BASE;
301 			century = 1;
302 			/* FALLTHROUGH */
303 		case 10:				/* yy */
304 			if (century)
305 				lt->tm_year += ATOI2(p);
306 			else {
307 				lt->tm_year = ATOI2(p);
308 				if (lt->tm_year < 69)	/* hack for 2000 ;-} */
309 					lt->tm_year += 2000 - TM_YEAR_BASE;
310 				else
311 					lt->tm_year += 1900 - TM_YEAR_BASE;
312 			}
313 			/* FALLTHROUGH */
314 		case 8:					/* mm */
315 			lt->tm_mon = ATOI2(p);
316 			if (lt->tm_mon > 12)
317 				badformat();
318 			--lt->tm_mon;		/* time struct is 0 - 11 */
319 			/* FALLTHROUGH */
320 		case 6:					/* dd */
321 			lt->tm_mday = ATOI2(p);
322 			if (lt->tm_mday > 31)
323 				badformat();
324 			/* FALLTHROUGH */
325 		case 4:					/* HH */
326 			lt->tm_hour = ATOI2(p);
327 			if (lt->tm_hour > 23)
328 				badformat();
329 			/* FALLTHROUGH */
330 		case 2:					/* MM */
331 			lt->tm_min = ATOI2(p);
332 			if (lt->tm_min > 59)
333 				badformat();
334 			break;
335 		default:
336 			badformat();
337 		}
338 	}
339 
340 	/* convert broken-down time to GMT clock time */
341 	if ((tval = mktime(lt)) == -1)
342 		errx(1, "nonexistent time");
343 
344 	if (!jflag) {
345 		utx.ut_type = OLD_TIME;
346 		memset(utx.ut_id, 0, sizeof(utx.ut_id));
347 		(void)gettimeofday(&utx.ut_tv, NULL);
348 		pututxline(&utx);
349 		tv.tv_sec = tval;
350 		tv.tv_usec = 0;
351 		if (settimeofday(&tv, NULL) != 0)
352 			err(1, "settimeofday (timeval)");
353 		utx.ut_type = NEW_TIME;
354 		(void)gettimeofday(&utx.ut_tv, NULL);
355 		pututxline(&utx);
356 
357 		if ((p = getlogin()) == NULL)
358 			p = "???";
359 		syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
360 	}
361 }
362 
363 static void
364 badformat(void)
365 {
366 	warnx("illegal time format");
367 	usage();
368 }
369 
370 static void
371 iso8601_usage(const char *badarg)
372 {
373 	errx(1, "invalid argument '%s' for -I", badarg);
374 }
375 
376 static void
377 multipleformats(void)
378 {
379 	errx(1, "multiple output formats specified");
380 }
381 
382 static void
383 usage(void)
384 {
385 	(void)fprintf(stderr, "%s\n%s\n%s\n",
386 	    "usage: date [-jnRu] [-I[date|hours|minutes|seconds]] [-f input_fmt]",
387 	    "            "
388 	    "[-r filename|seconds] [-v[+|-]val[y|m|w|d|H|M|S]]",
389 	    "            "
390 	    "[[[[[[cc]yy]mm]dd]HH]MM[.SS] | new_date] [+output_fmt]"
391 	    );
392 	exit(1);
393 }
394