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 #include <sys/param.h>
33 #include <sys/time.h>
34 #include <sys/stat.h>
35
36 #include <ctype.h>
37 #include <err.h>
38 #include <errno.h>
39 #include <locale.h>
40 #include <stdbool.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <syslog.h>
45 #include <unistd.h>
46 #include <utmpx.h>
47
48 #include "vary.h"
49
50 #ifndef TM_YEAR_BASE
51 #define TM_YEAR_BASE 1900
52 #endif
53
54 static void badformat(void);
55 static void iso8601_usage(const char *) __dead2;
56 static void multipleformats(void);
57 static void printdate(const char *);
58 static void printisodate(struct tm *, long);
59 static void setthetime(const char *, const char *, int, struct timespec *);
60 static size_t strftime_ns(char * __restrict, size_t, const char * __restrict,
61 const struct tm * __restrict, long);
62 static void usage(void) __dead2;
63
64 static const struct iso8601_fmt {
65 const char *refname;
66 const char *format_string;
67 } iso8601_fmts[] = {
68 { "date", "%Y-%m-%d" },
69 { "hours", "T%H" },
70 { "minutes", ":%M" },
71 { "seconds", ":%S" },
72 { "ns", ",%N" },
73 };
74 static const struct iso8601_fmt *iso8601_selected;
75
76 static const char *rfc2822_format = "%a, %d %b %Y %T %z";
77
78 int
main(int argc,char * argv[])79 main(int argc, char *argv[])
80 {
81 struct timespec ts;
82 int ch, rflag;
83 bool Iflag, jflag, Rflag;
84 const char *format;
85 char buf[1024];
86 char *fmt, *outzone = NULL;
87 char *tmp;
88 struct vary *v;
89 const struct vary *badv;
90 struct tm *lt;
91 struct stat sb;
92 size_t i;
93
94 v = NULL;
95 fmt = NULL;
96 (void) setlocale(LC_TIME, "");
97 rflag = 0;
98 Iflag = jflag = Rflag = 0;
99 ts.tv_sec = 0;
100 ts.tv_nsec = 0;
101 while ((ch = getopt(argc, argv, "f:I::jnRr:uv:z:")) != -1)
102 switch((char)ch) {
103 case 'f':
104 fmt = optarg;
105 break;
106 case 'I':
107 if (Rflag)
108 multipleformats();
109 Iflag = 1;
110 if (optarg == NULL) {
111 iso8601_selected = iso8601_fmts;
112 break;
113 }
114 for (i = 0; i < nitems(iso8601_fmts); i++)
115 if (strcmp(optarg, iso8601_fmts[i].refname) == 0)
116 break;
117 if (i == nitems(iso8601_fmts))
118 iso8601_usage(optarg);
119
120 iso8601_selected = &iso8601_fmts[i];
121 break;
122 case 'j':
123 jflag = 1; /* don't set time */
124 break;
125 case 'n':
126 break;
127 case 'R': /* RFC 2822 datetime format */
128 if (Iflag)
129 multipleformats();
130 Rflag = 1;
131 break;
132 case 'r': /* user specified seconds */
133 rflag = 1;
134 ts.tv_sec = strtoq(optarg, &tmp, 0);
135 if (*tmp != 0) {
136 if (stat(optarg, &sb) == 0) {
137 ts.tv_sec = sb.st_mtim.tv_sec;
138 ts.tv_nsec = sb.st_mtim.tv_nsec;
139 } else
140 usage();
141 }
142 break;
143 case 'u': /* do everything in UTC */
144 (void)setenv("TZ", "UTC0", 1);
145 break;
146 case 'z':
147 outzone = optarg;
148 break;
149 case 'v':
150 v = vary_append(v, optarg);
151 break;
152 default:
153 usage();
154 }
155 argc -= optind;
156 argv += optind;
157
158 if (!rflag && clock_gettime(CLOCK_REALTIME, &ts) == -1)
159 err(1, "clock_gettime");
160
161 format = "%+";
162
163 if (Rflag)
164 format = rfc2822_format;
165
166 /* allow the operands in any order */
167 if (*argv && **argv == '+') {
168 if (Iflag)
169 multipleformats();
170 format = *argv + 1;
171 ++argv;
172 }
173
174 if (*argv) {
175 setthetime(fmt, *argv, jflag, &ts);
176 ++argv;
177 } else if (fmt != NULL)
178 usage();
179
180 if (*argv && **argv == '+') {
181 if (Iflag)
182 multipleformats();
183 format = *argv + 1;
184 }
185
186 if (outzone != NULL && setenv("TZ", outzone, 1) != 0)
187 err(1, "setenv(TZ)");
188 lt = localtime(&ts.tv_sec);
189 if (lt == NULL)
190 errx(1, "invalid time");
191 badv = vary_apply(v, lt);
192 if (badv) {
193 fprintf(stderr, "%s: Cannot apply date adjustment\n",
194 badv->arg);
195 vary_destroy(v);
196 usage();
197 }
198 vary_destroy(v);
199
200 if (Iflag)
201 printisodate(lt, ts.tv_nsec);
202
203 if (format == rfc2822_format)
204 /*
205 * When using RFC 2822 datetime format, don't honor the
206 * locale.
207 */
208 setlocale(LC_TIME, "C");
209
210
211 (void)strftime_ns(buf, sizeof(buf), format, lt, ts.tv_nsec);
212 printdate(buf);
213 }
214
215 static void
printdate(const char * buf)216 printdate(const char *buf)
217 {
218 (void)printf("%s\n", buf);
219 if (fflush(stdout))
220 err(1, "stdout");
221 exit(EXIT_SUCCESS);
222 }
223
224 static void
printisodate(struct tm * lt,long nsec)225 printisodate(struct tm *lt, long nsec)
226 {
227 const struct iso8601_fmt *it;
228 char fmtbuf[64], buf[64], tzbuf[8];
229
230 fmtbuf[0] = 0;
231 for (it = iso8601_fmts; it <= iso8601_selected; it++)
232 strlcat(fmtbuf, it->format_string, sizeof(fmtbuf));
233
234 (void)strftime_ns(buf, sizeof(buf), fmtbuf, lt, nsec);
235
236 if (iso8601_selected > iso8601_fmts) {
237 (void)strftime_ns(tzbuf, sizeof(tzbuf), "%z", lt, nsec);
238 memmove(&tzbuf[4], &tzbuf[3], 3);
239 tzbuf[3] = ':';
240 strlcat(buf, tzbuf, sizeof(buf));
241 }
242
243 printdate(buf);
244 }
245
246 #define ATOI2(s) ((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))
247
248 static void
setthetime(const char * fmt,const char * p,int jflag,struct timespec * ts)249 setthetime(const char *fmt, const char *p, int jflag, struct timespec *ts)
250 {
251 struct utmpx utx;
252 struct tm *lt;
253 const char *dot, *t;
254 int century;
255
256 lt = localtime(&ts->tv_sec);
257 if (lt == NULL)
258 errx(1, "invalid time");
259 lt->tm_isdst = -1; /* divine correct DST */
260
261 if (fmt != NULL) {
262 t = strptime(p, fmt, lt);
263 if (t == NULL) {
264 fprintf(stderr, "Failed conversion of ``%s''"
265 " using format ``%s''\n", p, fmt);
266 badformat();
267 } else if (*t != '\0')
268 fprintf(stderr, "Warning: Ignoring %ld extraneous"
269 " characters in date string (%s)\n",
270 (long) strlen(t), t);
271 } else {
272 for (t = p, dot = NULL; *t; ++t) {
273 if (isdigit(*t))
274 continue;
275 if (*t == '.' && dot == NULL) {
276 dot = t;
277 continue;
278 }
279 badformat();
280 }
281
282 if (dot != NULL) { /* .ss */
283 dot++; /* *dot++ = '\0'; */
284 if (strlen(dot) != 2)
285 badformat();
286 lt->tm_sec = ATOI2(dot);
287 if (lt->tm_sec > 61)
288 badformat();
289 } else
290 lt->tm_sec = 0;
291
292 century = 0;
293 /* if p has a ".ss" field then let's pretend it's not there */
294 switch (strlen(p) - ((dot != NULL) ? 3 : 0)) {
295 case 12: /* cc */
296 lt->tm_year = ATOI2(p) * 100 - TM_YEAR_BASE;
297 century = 1;
298 /* FALLTHROUGH */
299 case 10: /* yy */
300 if (century)
301 lt->tm_year += ATOI2(p);
302 else {
303 lt->tm_year = ATOI2(p);
304 if (lt->tm_year < 69) /* hack for 2000 ;-} */
305 lt->tm_year += 2000 - TM_YEAR_BASE;
306 else
307 lt->tm_year += 1900 - TM_YEAR_BASE;
308 }
309 /* FALLTHROUGH */
310 case 8: /* mm */
311 lt->tm_mon = ATOI2(p);
312 if (lt->tm_mon > 12)
313 badformat();
314 --lt->tm_mon; /* time struct is 0 - 11 */
315 /* FALLTHROUGH */
316 case 6: /* dd */
317 lt->tm_mday = ATOI2(p);
318 if (lt->tm_mday > 31)
319 badformat();
320 /* FALLTHROUGH */
321 case 4: /* HH */
322 lt->tm_hour = ATOI2(p);
323 if (lt->tm_hour > 23)
324 badformat();
325 /* FALLTHROUGH */
326 case 2: /* MM */
327 lt->tm_min = ATOI2(p);
328 if (lt->tm_min > 59)
329 badformat();
330 break;
331 default:
332 badformat();
333 }
334 }
335
336 /* convert broken-down time to GMT clock time */
337 lt->tm_yday = -1;
338 ts->tv_sec = mktime(lt);
339 if (lt->tm_yday == -1)
340 errx(1, "nonexistent time");
341 ts->tv_nsec = 0;
342
343 if (!jflag) {
344 utx.ut_type = OLD_TIME;
345 memset(utx.ut_id, 0, sizeof(utx.ut_id));
346 (void)gettimeofday(&utx.ut_tv, NULL);
347 pututxline(&utx);
348 if (clock_settime(CLOCK_REALTIME, ts) != 0)
349 err(1, "clock_settime");
350 utx.ut_type = NEW_TIME;
351 (void)gettimeofday(&utx.ut_tv, NULL);
352 pututxline(&utx);
353
354 if ((p = getlogin()) == NULL)
355 p = "???";
356 syslog(LOG_AUTH | LOG_NOTICE, "date set by %s", p);
357 }
358 }
359
360 /*
361 * The strftime_ns function is a wrapper around strftime(3), which adds support
362 * for features absent from strftime(3). Currently, the only extra feature is
363 * support for %N, the nanosecond conversion specification.
364 *
365 * The functions scans the format string for the non-standard conversion
366 * specifications and replaces them with the date and time values before
367 * passing the format string to strftime(3). The handling of the non-standard
368 * conversion specifications happens before the call to strftime(3) to handle
369 * cases like "%%N" correctly ("%%N" should yield "%N" instead of nanoseconds).
370 */
371 static size_t
strftime_ns(char * __restrict s,size_t maxsize,const char * __restrict format,const struct tm * __restrict t,long nsec)372 strftime_ns(char * __restrict s, size_t maxsize, const char * __restrict format,
373 const struct tm * __restrict t, long nsec)
374 {
375 size_t prefixlen;
376 size_t ret;
377 char *newformat;
378 char *oldformat;
379 const char *prefix;
380 const char *suffix;
381 const char *tok;
382 bool seen_percent;
383
384 seen_percent = false;
385 if (asprintf(&newformat, "%s", format) < 0)
386 err(1, "asprintf");
387 tok = newformat;
388 for (tok = newformat; *tok != '\0'; tok++) {
389 switch (*tok) {
390 case '%':
391 /*
392 * If the previous token was a percent sign,
393 * then there are two percent tokens in a row.
394 */
395 if (seen_percent)
396 seen_percent = false;
397 else
398 seen_percent = true;
399 break;
400 case 'N':
401 if (seen_percent) {
402 oldformat = newformat;
403 prefix = oldformat;
404 prefixlen = tok - oldformat - 1;
405 suffix = tok + 1;
406 /*
407 * Construct a new format string from the
408 * prefix (i.e., the part of the old fromat
409 * from its beginning to the currently handled
410 * "%N" conversion specification, the
411 * nanoseconds, and the suffix (i.e., the part
412 * of the old format from the next token to the
413 * end).
414 */
415 if (asprintf(&newformat, "%.*s%.9ld%s",
416 (int)prefixlen, prefix, nsec,
417 suffix) < 0) {
418 err(1, "asprintf");
419 }
420 free(oldformat);
421 tok = newformat + prefixlen + 9;
422 }
423 seen_percent = false;
424 break;
425 default:
426 seen_percent = false;
427 break;
428 }
429 }
430
431 ret = strftime(s, maxsize, newformat, t);
432 free(newformat);
433 return (ret);
434 }
435
436 static void
badformat(void)437 badformat(void)
438 {
439 warnx("illegal time format");
440 usage();
441 }
442
443 static void
iso8601_usage(const char * badarg)444 iso8601_usage(const char *badarg)
445 {
446 errx(1, "invalid argument '%s' for -I", badarg);
447 }
448
449 static void
multipleformats(void)450 multipleformats(void)
451 {
452 errx(1, "multiple output formats specified");
453 }
454
455 static void
usage(void)456 usage(void)
457 {
458 (void)fprintf(stderr, "%s\n%s\n%s\n",
459 "usage: date [-jnRu] [-I[date|hours|minutes|seconds|ns]] [-f input_fmt]",
460 " "
461 "[ -z output_zone ] [-r filename|seconds] [-v[+|-]val[y|m|w|d|H|M|S]]",
462 " "
463 "[[[[[[cc]yy]mm]dd]HH]MM[.SS] | new_date] [+output_fmt]"
464 );
465 exit(1);
466 }
467