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
33static 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
40static 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
68static time_t tval;
69
70static void badformat(void);
71static void iso8601_usage(const char *);
72static void multipleformats(void);
73static void printdate(const char *);
74static void printisodate(struct tm *);
75static void setthetime(const char *, const char *, int);
76static void usage(void);
77
78static 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};
87static const struct iso8601_fmt *iso8601_selected;
88
89static const char *rfc2822_format = "%a, %d %b %Y %T %z";
90
91int
92main(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
218static void
219printdate(const char *buf)
220{
221	(void)printf("%s\n", buf);
222	if (fflush(stdout))
223		err(1, "stdout");
224	exit(EXIT_SUCCESS);
225}
226
227static void
228printisodate(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
251static void
252setthetime(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
363static void
364badformat(void)
365{
366	warnx("illegal time format");
367	usage();
368}
369
370static void
371iso8601_usage(const char *badarg)
372{
373	errx(1, "invalid argument '%s' for -I", badarg);
374}
375
376static void
377multipleformats(void)
378{
379	errx(1, "multiple output formats specified");
380}
381
382static void
383usage(void)
384{
385	(void)fprintf(stderr, "%s\n%s\n%s\n",
386	    "usage: date [-jnRu] [-r seconds|file] [-v[+|-]val[ymwdHMS]]",
387	    "            "
388	    "[-I[date | hours | minutes | seconds]]",
389	    "            "
390	    "[-f fmt date | [[[[[cc]yy]mm]dd]HH]MM[.ss]] [+format]"
391	    );
392	exit(1);
393}
394