xref: /netbsd-src/bin/date/date.c (revision 82d56013d7b633d116a93943de88e08335357a7c)
1 /* $NetBSD: date.c,v 1.62 2021/05/26 20:19:51 christos Exp $ */
2 
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 #if HAVE_NBTOOL_CONFIG_H
33 #include "nbtool_config.h"
34 #endif
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 __COPYRIGHT(
39 "@(#) Copyright (c) 1985, 1987, 1988, 1993\
40  The Regents of the University of California.  All rights reserved.");
41 #endif /* not lint */
42 
43 #ifndef lint
44 #if 0
45 static char sccsid[] = "@(#)date.c	8.2 (Berkeley) 4/28/95";
46 #else
47 __RCSID("$NetBSD: date.c,v 1.62 2021/05/26 20:19:51 christos Exp $");
48 #endif
49 #endif /* not lint */
50 
51 #include <sys/param.h>
52 #include <sys/time.h>
53 
54 #include <ctype.h>
55 #include <err.h>
56 #include <fcntl.h>
57 #include <errno.h>
58 #include <locale.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62 #include <syslog.h>
63 #include <time.h>
64 #include <tzfile.h>
65 #include <unistd.h>
66 #include <util.h>
67 
68 #include "extern.h"
69 
70 static time_t tval;
71 static int aflag, jflag, rflag, nflag;
72 
73 __dead static void badcanotime(const char *, const char *, size_t);
74 static void setthetime(const char *);
75 __dead static void usage(void);
76 
77 int
78 main(int argc, char *argv[])
79 {
80 	char *buf;
81 	size_t bufsiz;
82 	const char *format;
83 	int ch;
84 	long long val;
85 	struct tm *tm;
86 
87 	setprogname(argv[0]);
88 	(void)setlocale(LC_ALL, "");
89 
90 	while ((ch = getopt(argc, argv, "ad:jnr:u")) != -1) {
91 		switch (ch) {
92 		case 'a':		/* adjust time slowly */
93 			aflag = 1;
94 			nflag = 1;
95 			break;
96 		case 'd':
97 #ifndef HAVE_NBTOOL_CONFIG_H
98 			rflag = 1;
99 			tval = parsedate(optarg, NULL, NULL);
100 			if (tval == -1) {
101 				errx(EXIT_FAILURE,
102 				    "%s: Unrecognized date format", optarg);
103 			}
104 			break;
105 #else
106 			errx(EXIT_FAILURE,
107 			    "-d not supported in the tool version");
108 #endif
109 		case 'j':		/* don't set time */
110 			jflag = 1;
111 			break;
112 		case 'n':		/* don't set network */
113 			nflag = 1;
114 			break;
115 		case 'r':		/* user specified seconds */
116 			if (optarg[0] == '\0') {
117 				errx(EXIT_FAILURE, "<empty>: Invalid number");
118 			}
119 			errno = 0;
120 			val = strtoll(optarg, &buf, 0);
121 			if (errno) {
122 				err(EXIT_FAILURE, "%s", optarg);
123 			}
124 			if (optarg[0] == '\0' || *buf != '\0') {
125 				errx(EXIT_FAILURE,
126 				    "%s: Invalid number", optarg);
127 			}
128 			rflag = 1;
129 			tval = (time_t)val;
130 			break;
131 		case 'u':		/* do everything in UTC */
132 			(void)setenv("TZ", "UTC0", 1);
133 			break;
134 		default:
135 			usage();
136 		}
137 	}
138 	argc -= optind;
139 	argv += optind;
140 
141 	if (!rflag && time(&tval) == -1)
142 		err(EXIT_FAILURE, "time");
143 
144 
145 	/* allow the operands in any order */
146 	if (*argv && **argv == '+') {
147 		format = *argv;
148 		++argv;
149 	} else
150 		format = "+%a %b %e %H:%M:%S %Z %Y";
151 
152 	if (*argv) {
153 		setthetime(*argv);
154 		++argv;
155 	}
156 
157 	if (*argv && **argv == '+')
158 		format = *argv;
159 
160 	if ((buf = malloc(bufsiz = 1024)) == NULL)
161 		goto bad;
162 
163 	if ((tm = localtime(&tval)) == NULL)
164 		err(EXIT_FAILURE, "%lld: localtime", (long long)tval);
165 
166 	while (strftime(buf, bufsiz, format, tm) == 0)
167 		if ((buf = realloc(buf, bufsiz <<= 1)) == NULL)
168 			goto bad;
169 
170 	(void)printf("%s\n", buf + 1);
171 	free(buf);
172 	return 0;
173 bad:
174 	err(EXIT_FAILURE, "Cannot allocate format buffer");
175 }
176 
177 static void
178 badcanotime(const char *msg, const char *val, size_t where)
179 {
180 	warnx("%s in canonical time", msg);
181 	warnx("%s", val);
182 	warnx("%*s", (int)where + 1, "^");
183 	usage();
184 }
185 
186 #define ATOI2(s) ((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))
187 
188 static void
189 setthetime(const char *p)
190 {
191 	struct timeval tv;
192 	time_t new_time;
193 	struct tm *lt;
194 	const char *dot, *t, *op;
195 	size_t len;
196 	int yearset;
197 
198 	for (t = p, dot = NULL; *t; ++t) {
199 		if (*t == '.') {
200 			if (dot == NULL) {
201 				dot = t;
202 			} else {
203 				badcanotime("Unexpected dot", p, t - p);
204 			}
205 		} else if (!isdigit((unsigned char)*t)) {
206 			badcanotime("Expected digit", p, t - p);
207 		}
208 	}
209 
210 	if ((lt = localtime(&tval)) == NULL)
211 		err(EXIT_FAILURE, "%lld: localtime", (long long)tval);
212 
213 	lt->tm_isdst = -1;			/* Divine correct DST */
214 
215 	if (dot != NULL) {			/* .ss */
216 		len = strlen(dot);
217 		if (len > 3) {
218 			badcanotime("Unexpected digit after seconds field",
219 				    p, strlen(p) - 1);
220 		} else if (len < 3) {
221 			badcanotime("Expected digit in seconds field",
222 				    p, strlen(p));
223 		}
224 		++dot;
225 		lt->tm_sec = ATOI2(dot);
226 		if (lt->tm_sec > 61)
227 			badcanotime("Seconds out of range", p, strlen(p) - 1);
228 	} else {
229 		len = 0;
230 		lt->tm_sec = 0;
231 	}
232 
233 	op = p;
234 	yearset = 0;
235 	switch (strlen(p) - len) {
236 	case 12:				/* cc */
237 		lt->tm_year = ATOI2(p) * 100 - TM_YEAR_BASE;
238 		if (lt->tm_year < 0)
239 			badcanotime("Year before 1900", op, p - op + 1);
240 		yearset = 1;
241 		/* FALLTHROUGH */
242 	case 10:				/* yy */
243 		if (yearset) {
244 			lt->tm_year += ATOI2(p);
245 		} else {
246 			yearset = ATOI2(p);
247 			if (yearset < 69)
248 				lt->tm_year = yearset + 2000 - TM_YEAR_BASE;
249 			else
250 				lt->tm_year = yearset + 1900 - TM_YEAR_BASE;
251 		}
252 		/* FALLTHROUGH */
253 	case 8:					/* mm */
254 		lt->tm_mon = ATOI2(p);
255 		if (lt->tm_mon > 12 || lt->tm_mon == 0)
256 			badcanotime("Month out of range", op, p - op - 1);
257 		--lt->tm_mon;			/* time struct is 0 - 11 */
258 		/* FALLTHROUGH */
259 	case 6:					/* dd */
260 		lt->tm_mday = ATOI2(p);
261 		switch (lt->tm_mon) {
262 		case 0:
263 		case 2:
264 		case 4:
265 		case 6:
266 		case 7:
267 		case 9:
268 		case 11:
269 			if (lt->tm_mday > 31 || lt->tm_mday == 0)
270 				badcanotime("Day out of range (max 31)",
271 					    op, p - op - 1);
272 			break;
273 		case 3:
274 		case 5:
275 		case 8:
276 		case 10:
277 			if (lt->tm_mday > 30 || lt->tm_mday == 0)
278 				badcanotime("Day out of range (max 30)",
279 					    op, p - op - 1);
280 			break;
281 		case 1:
282 			if (isleap(lt->tm_year + TM_YEAR_BASE)) {
283 				if (lt->tm_mday > 29 || lt->tm_mday == 0) {
284 					badcanotime("Day out of range "
285 						    "(max 29)",
286 						    op, p - op - 1);
287 				}
288 			} else {
289 				if (lt->tm_mday > 28 || lt->tm_mday == 0) {
290 					badcanotime("Day out of range "
291 						    "(max 28)",
292 						    op, p - op - 1);
293 				}
294 			}
295 			break;
296 		default:
297 			/*
298 			 * If the month was given, it's already been
299 			 * checked.  If a bad value came back from
300 			 * localtime, something's badly broken.
301 			 * (make this an assertion?)
302 			 */
303 			errx(EXIT_FAILURE, "localtime gave invalid month %d",
304 			    lt->tm_mon);
305 		}
306 		/* FALLTHROUGH */
307 	case 4:					/* hh */
308 		lt->tm_hour = ATOI2(p);
309 		if (lt->tm_hour > 23)
310 			badcanotime("Hour out of range", op, p - op - 1);
311 		/* FALLTHROUGH */
312 	case 2:					/* mm */
313 		lt->tm_min = ATOI2(p);
314 		if (lt->tm_min > 59)
315 			badcanotime("Minute out of range", op, p - op - 1);
316 		break;
317 	case 0:					/* was just .sss */
318 		if (len != 0)
319 			break;
320 		/* FALLTHROUGH */
321 	default:
322 	    if (strlen(p) - len > 12) {
323 		    badcanotime("Too many digits", p, 12);
324 	    } else {
325 		    badcanotime("Not enough digits", p, strlen(p) - len);
326 	    }
327 	}
328 
329 	/* convert broken-down time to UTC clock time */
330 	if ((new_time = mktime(lt)) == -1) {
331 		/* Can this actually happen? */
332 		err(EXIT_FAILURE, "%s: mktime", op);
333 	}
334 
335 	/* if jflag is set, don't actually change the time, just return */
336 	if (jflag) {
337 		tval = new_time;
338 		return;
339 	}
340 
341 	/* set the time */
342 #ifndef HAVE_NBTOOL_CONFIG_H
343 	if (nflag || netsettime(new_time)) {
344 		logwtmp("|", "date", "");
345 		if (aflag) {
346 			tv.tv_sec = new_time - tval;
347 			tv.tv_usec = 0;
348 			if (adjtime(&tv, NULL))
349 				err(EXIT_FAILURE, "adjtime");
350 		} else {
351 			tval = new_time;
352 			tv.tv_sec = tval;
353 			tv.tv_usec = 0;
354 			if (settimeofday(&tv, NULL))
355 				err(EXIT_FAILURE, "settimeofday");
356 		}
357 		logwtmp("{", "date", "");
358 	}
359 #else
360 	errx(EXIT_FAILURE, "Can't set the time in the tools version");
361 #endif
362 
363 	if ((p = getlogin()) == NULL)
364 		p = "???";
365 	syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
366 }
367 
368 static void
369 usage(void)
370 {
371 	(void)fprintf(stderr,
372 	    "Usage: %s [-ajnu] [-d date] [-r seconds] [+format]",
373 	    getprogname());
374 	(void)fprintf(stderr, " [[[[[[CC]yy]mm]dd]HH]MM[.SS]]\n");
375 	exit(EXIT_FAILURE);
376 	/* NOTREACHED */
377 }
378