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utils-std

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

date.c (9362B)

    

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