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utils-std

Collection of commonly available Unix tools git clone https://anongit.hacktivis.me/git/utils-std.git/

date.c (9433B)

    

  1. // utils-std: Collection of commonly available Unix tools
  2. // SPDX-FileCopyrightText: 2017 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
  3. // SPDX-License-Identifier: MPL-2.0
  5. #define _DEFAULT_SOURCE // tm_gmtoff/tm_zone
  6. #define _POSIX_C_SOURCE 200809L
  7. #define _XOPEN_SOURCE 700 // strptime is in XSI
  9. #include "../config.h"
  10. #include "../libutils/datetime_parse.h" /* datetime_parse */
  11. #include "../libutils/getopt_nolong.h"
  13. #include <assert.h>
  14. #include <errno.h>
  15. #include <inttypes.h> /* PRId64 */
  16. #include <locale.h>   /* setlocale() */
  17. #include <stdbool.h>
  18. #include <stdio.h>  /* BUFSIZ, fprintf(), puts() */
  19. #include <stdlib.h> /* strtol() */
  20. #include <string.h> /* strerror */
  21. #include <time.h>   /* time, localtime, tm, strftime, strptime, clock_settime */
  22. #include <unistd.h> /* getopt(), opt… */
  23. #ifdef HAS_GETOPT_LONG
  24. #include <getopt.h>
  25. #endif
  27. const char *argv0 = "date";
  29. static size_t
  30. date_strftime(char *restrict buf,
  31.               size_t buflen,
  32.               const char *restrict fmt,
  33.               const struct tm *restrict tm,
  34.               long nsec)
  35. {
  36. 	size_t fmtlen = strlen(fmt);
  37. 	size_t printed = 0;
  39. 	if(fmtlen == 0)
  40. 	{
  41. 		buf[0] = '\0';
  42. 		return 0;
  43. 	}
  45. 	for(size_t i = 0; i < fmtlen;)
  46. 	{
  47. 		// size taken from musl strftime
  48. 		static char fmt_buf[100] = "";
  49. 		size_t fmt_bufi = 0;
  51. 		if(fmt[i] == '%')
  52. 		{
  53. 			fmt_buf[fmt_bufi++] = fmt[i++];
  55. 			if(fmt[i] == '%') // handle '%%'
  56. 			{
  57. 				*buf = '%';
  58. 				buf++;
  59. 				buflen--;
  60. 				printed++;
  61. 				i++;
  62. 				continue;
  63. 			}
  64. 		}
  66. 		for(; fmt[i] != '%' && i < fmtlen;)
  67. 		{
  68. 			fmt_buf[fmt_bufi++] = fmt[i++];
  69. 			assert(fmt_bufi < 100);
  70. 		}
  72. 		fmt_buf[fmt_bufi] = '\0';
  74. 		if(fmt_buf[0] == '%' && fmt_buf[1] == ':' && fmt_buf[2] == 'z')
  75. 		{
  76. 			size_t got =
  77. 			    snprintf(buf, buflen, "%+.2ld:%.2ld", tm->tm_gmtoff / 3600, tm->tm_gmtoff % 3600 / 60);
  78. 			if(got == 0) return got;
  80. 			buf += got;
  81. 			buflen -= got;
  82. 			printed += got;
  83. 		}
  84. 		else if(fmt_buf[0] == '%' && fmt_buf[1] == 'N')
  85. 		{
  86. 			size_t got = snprintf(buf, buflen, "%09ld", nsec);
  87. 			if(got == 0) return got;
  89. 			buf += got;
  90. 			buflen -= got;
  91. 			printed += got;
  92. 		}
  93. 		else
  94. 		{
  95. 			size_t got = strftime(buf, buflen, fmt_buf, tm);
  96. 			if(got == 0) return got;
  98. 			buf += got;
  99. 			buflen -= got;
  100. 			printed += got;
  101. 		}
  102. 	}
  104. 	return printed;
  105. }
  107. static void
  108. usage(void)
  109. {
  110. 	fprintf(stderr, "\
  111. Usage:\n\
  112. 	date [-jRu] [-I iso_fmt] [-d datetime | -r epoch] [+format]\n\
  113. 	date [-jRu] [-I iso_fmt] mmddHHMM[[CC]yy] [+format]\n\
  114. 	date [-jRu] [-I iso_fmt] -f now_format now [+format]\n\
  115. ");
  116. }
  118. int
  119. main(int argc, char *argv[])
  120. {
  121. 	char outstr[BUFSIZ] = "";
  122. 	struct tm tm = {
  123. 	    .tm_year = 0,
  124. 	    .tm_mon = 0,
  125. 	    .tm_mday = 0,
  126. 	    .tm_hour = 0,
  127. 	    .tm_min = 0,
  128. 	    .tm_sec = 0,
  129. 	    .tm_isdst = -1, // unknown if DST is in effect
  130. 	    .tm_gmtoff = 0,
  131. 	    .tm_zone = NULL,
  132. 	};
  133. 	struct timespec tp = {
  134. 	    .tv_sec = 0,
  135. 	    .tv_nsec = 0,
  136. 	};
  137. 	const char *format = "%c";
  138. 	const char *input_format = NULL;
  139. 	int uflag = 0;
  140. 	int dflag = 0, rflag = 0;
  141. 	bool jflag = false;
  142. 	bool settime = false;
  144. 	char *lc_all = setlocale(LC_ALL, "");
  145. 	if(lc_all == NULL)
  146. 	{
  147. 		fprintf(stderr,
  148. 		        "%s: warning: Failed loading locales. setlocale(LC_ALL, \"\"): %s\n",
  149. 		        argv0,
  150. 		        strerror(errno));
  151. 	}
  152. 	errno = 0;
  154. 	if(clock_gettime(CLOCK_REALTIME, &tp) != 0)
  155. 	{
  156. 		fprintf(stderr, "%s: error: Failed getting current time: %s\n", argv0, strerror(errno));
  157. 		return 1;
  158. 	}
  160. #ifdef HAS_GETOPT_LONG
  161. 	// Strictly for GNUisms compatibility so no long-only options
  162. 	// clang-format off
  163. 	static struct option opts[] = {
  164. 		{"date", required_argument, NULL, 'd'},
  165. 		{"iso-8601", optional_argument, NULL, 'I'},
  166. 		{"rfc-email", no_argument, NULL, 'R'},
  167. 		{"universal", no_argument, NULL, 'u'},
  168. 		{"utc", no_argument, NULL, 'u'},
  169. 		{0, 0, 0, 0},
  170. 	};
  171. 	// clang-format on
  173. 	// Need + as first character to get POSIX-style option parsing
  174. 	// Assume all getopt_long implementations support :: for optional args
  175. 	for(int c = -1; (c = getopt_long(argc, argv, "+:d:f:I::jr:Ru", opts, NULL)) != -1;)
  176. #else
  177. 	for(int c = -1; (c = getopt_nolong(argc, argv, ":d:f:I:jr:Ru")) != -1;)
  178. #endif
  179. 	{
  180. 		const char *errstr = NULL;
  181. 		switch(c)
  182. 		{
  183. 		case 'd': /* Custom datetime */
  184. 			if(input_format != NULL)
  185. 			{
  186. 				fprintf(stderr, "%s: error: Cannot both use '-d' and '-f'\n", argv0);
  187. 				return 1;
  188. 			}
  189. 			if(rflag == 1)
  190. 			{
  191. 				fprintf(stderr, "%s: error: Cannot both use '-d' and '-r'\n", argv0);
  192. 				return 1;
  193. 			}
  195. 			datetime_parse(optarg, &tm, &tp.tv_nsec, &errstr);
  196. 			dflag = 1;
  197. 			if(errstr != NULL)
  198. 			{
  199. 				fprintf(stderr, "%s: error: datetime_parse(\"%s\", …): %s\n", argv0, optarg, errstr);
  200. 				return 1;
  201. 			}
  203. 			tp.tv_sec = mktime_tz(&tm);
  204. 			if(tp.tv_sec == (time_t)-1)
  205. 			{
  206. 				fprintf(stderr, "%s: error: mktime: %s\n", argv0, strerror(errno));
  207. 				return 1;
  208. 			}
  209. 			errno = 0;
  211. 			break;
  212. 		case 'f': /* input datetime format */
  213. 			if(dflag == 1)
  214. 			{
  215. 				fprintf(stderr, "%s: error: Cannot both use '-d' and '-f'\n", argv0);
  216. 				return 1;
  217. 			}
  218. 			if(rflag == 1)
  219. 			{
  220. 				fprintf(stderr, "%s: error: Cannot both use '-f' and '-r'\n", argv0);
  221. 				return 1;
  222. 			}
  224. 			input_format = optarg;
  225. 			settime = true;
  226. 			break;
  227. 		case 'r': /* seconds relative to epoch */
  228. 		{
  229. 			if(input_format != NULL)
  230. 			{
  231. 				fprintf(stderr, "%s: error: Cannot both use '-f' and '-r'\n", argv0);
  232. 				return 1;
  233. 			}
  234. 			if(dflag == 1)
  235. 			{
  236. 				fprintf(stderr, "%s: error: Cannot both use '-d' and '-r'\n", argv0);
  237. 				return 1;
  238. 			}
  240. 			char *endptr = NULL;
  241. 			errno = 0;
  242. 			tp.tv_sec = strtol(optarg, &endptr, 10);
  243. 			if(errno != 0)
  244. 			{
  245. 				fprintf(stderr, "%s: error: Failed parsing '-r %s'\n", argv0, optarg);
  246. 				return 1;
  247. 			}
  248. 			if(!(endptr == NULL || *endptr == '\0'))
  249. 			{
  250. 				fprintf(stderr, "%s: error: Invalid characters in '-r %s': %s\n", argv0, optarg, endptr);
  251. 				return 1;
  252. 			}
  253. 			break;
  254. 		}
  255. 		case 'R': /* Email (RFC 5322) format */
  256. 			format = "%a, %d %b %Y %H:%M:%S %z";
  257. 			break;
  258. 		case 'u': /* UTC timezone */
  259. 			uflag++;
  260. 			setenv("TZ", "UTC", 1);
  261. 			tzset();
  262. 			break;
  263. 		case 'I': /* ISO 8601 */
  264. 			if(optarg)
  265. 			{
  266. 				/* note: %:z (±ZZ:ZZ) and %N (nanoseconds) are date(1) GNU-isms absent from C libraries including glibc */
  267. 				switch(optarg[0])
  268. 				{
  269. 				case 'h': // hours
  270. 					format = "%Y-%m-%dT%H%:z";
  271. 					break;
  272. 				case 'm': // minutes
  273. 					format = "%Y-%m-%dT%H:%M%:z";
  274. 					break;
  275. 				case 's': // seconds
  276. 					format = "%Y-%m-%dT%H:%M:%S%:z";
  277. 					break;
  278. 				case 'n': // ns, nanoseconds
  279. 					format = "%Y-%m-%dT%H:%M:%S,%N%:z";
  280. 					break;
  281. 				case 'd': // date
  282. 				default:
  283. 					format = "%Y-%m-%d";
  284. 					break;
  285. 				}
  286. 			}
  287. 			else
  288. 				format = "%Y-%m-%d";
  289. 			break;
  290. 		case 'j':
  291. 			jflag = true;
  292. 			break;
  293. 		case ':':
  294. 			fprintf(stderr, "%s: error: Missing operand for option: '-%c'\n", argv0, optopt);
  295. 			usage();
  296. 			return 1;
  297. 		case '?':
  298. 			GETOPT_UNKNOWN_OPT
  299. 			usage();
  300. 			return 1;
  301. 		}
  302. 	}
  304. 	argc -= optind;
  305. 	argv += optind;
  307. 	if(uflag)
  308. 	{
  309. 		if(gmtime_r(&tp.tv_sec, &tm) == NULL)
  310. 		{
  311. 			fprintf(stderr, "%s: error: gmtime_r: %s\n", argv0, strerror(errno));
  312. 			return 1;
  313. 		}
  314. 	}
  315. 	else
  316. 	{
  317. 		if(localtime_r(&tp.tv_sec, &tm) == NULL)
  318. 		{
  319. 			fprintf(stderr, "%s: error: localtime_r: %s\n", argv0, strerror(errno));
  320. 			return 1;
  321. 		}
  322. 	}
  324. 	if(argc > 0 && input_format != NULL)
  325. 	{
  326. 		char *res = strptime(argv[0], input_format, &tm);
  328. 		if(res == NULL)
  329. 		{
  330. 			fprintf(stderr,
  331. 			        "%s: error: strptime(\"%s\", \"%s\", …) as passed by '-f' option failed\n",
  332. 			        argv0,
  333. 			        argv[0],
  334. 			        input_format);
  335. 			return 1;
  336. 		}
  338. 		tp.tv_sec = mktime_tz(&tm);
  339. 		tp.tv_nsec = 0;
  340. 		if(tp.tv_sec == (time_t)-1)
  341. 		{
  342. 			fprintf(stderr, "%s: error: mktime: %s\n", argv0, strerror(errno));
  343. 			return 1;
  344. 		}
  345. 		errno = 0;
  347. 		argv++;
  348. 		argc--;
  349. 	}
  351. 	if(input_format == NULL && argc > 0 && *argv && **argv != '+')
  352. 	{
  353. 		const char *fmt = "%m%d%H%M";
  354. 		char *s = strptime(argv[0], fmt, &tm);
  355. 		if(s == NULL)
  356. 		{
  357. 			fprintf(stderr, "%s: error: strptime(\"%s\", \"%s\", …) returned NULL\n", argv0, *argv, fmt);
  358. 			return 1;
  359. 		}
  361. 		size_t rem = strlen(s);
  362. 		if(rem > 0)
  363. 		{
  364. 			switch(rem)
  365. 			{
  366. 			case 2:
  367. 				fmt = "%y";
  368. 				break;
  369. 			case 4:
  370. 				fmt = "%Y";
  371. 				break;
  372. 			default:
  373. 				fprintf(stderr,
  374. 				        "%s: error: Got %zu trailing characters after \"%s\" for mmddHHMM\n",
  375. 				        argv0,
  376. 				        rem,
  377. 				        fmt);
  378. 				return 1;
  379. 			}
  381. 			s = strptime(s, fmt, &tm);
  382. 			if(s == NULL)
  383. 			{
  384. 				fprintf(
  385. 				    stderr, "%s: error: strptime(\"%s\", \"%s\", …) returned NULL\n", argv0, *argv, fmt);
  386. 				return 1;
  387. 			}
  388. 		}
  390. 		tp.tv_sec = mktime(&tm);
  391. 		tp.tv_nsec = 0;
  392. 		if(tp.tv_sec == (time_t)-1)
  393. 		{
  394. 			fprintf(stderr, "%s: error: mktime: %s\n", argv0, strerror(errno));
  395. 			return 1;
  396. 		}
  397. 		errno = 0;
  399. 		argv++;
  400. 		argc--;
  401. 		settime = true;
  402. 	}
  404. 	if(settime && !jflag)
  405. 	{
  406. 		if(clock_settime(CLOCK_REALTIME, &tp) != 0)
  407. 		{
  408. 			fprintf(stderr,
  409. 			        "%s: error: clock_settime(CLOCK_REALTIME, {%" PRId64 ", %" PRId64 "}): %s\n",
  410. 			        argv0,
  411. 			        (int64_t)tp.tv_sec,
  412. 			        (int64_t)tp.tv_nsec,
  413. 			        strerror(errno));
  414. 			return 1;
  415. 		}
  416. 	}
  418. 	if(argc > 0 && *argv && **argv == '+')
  419. 	{
  420. 		format = *argv + 1;
  422. 		argv++;
  423. 		argc--;
  424. 	}
  426. 	errno = 0;
  427. 	if(date_strftime(outstr, sizeof(outstr), format, &tm, tp.tv_nsec) == 0 && errno != 0)
  428. 	{
  429. 		fprintf(stderr, "%s: error: Failed formatting time: %s\n", argv0, strerror(errno));
  430. 		return 1;
  431. 	}
  433. 	if(puts(outstr) < 0)
  434. 	{
  435. 		fprintf(stderr, "%s: error: Failed writing time: %s\n", argv0, strerror(errno));
  436. 		return 1;
  437. 	}
  439. 	return 0;
  440. }