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utils-std

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

touch.c (6843B)

    

  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 _XOPEN_SOURCE 700       // strptime (NetBSD)
  7. #define _POSIX_C_SOURCE 200809L // O_NOFOLLOW, st_atim/st_mtim
  9. #ifdef __OpenBSD__  // as seen on OpenBSD 7.7
  10. #define _BSD_SOURCE // O_NOFOLLOW
  11. #endif
  13. #include "../config.h"
  14. #include "../lib/bitmasks.h"            /* FIELD_* */
  15. #include "../libutils/datetime_parse.h" /* datetime_parse */
  16. #include "../libutils/getopt_nolong.h"
  18. #include <assert.h>
  19. #include <errno.h>    /* errno */
  20. #include <fcntl.h>    /* open */
  21. #include <stdbool.h>  /* bool */
  22. #include <stdio.h>    /* perror */
  23. #include <string.h>   /* strrchr, strlen */
  24. #include <sys/stat.h> /* futimens, stat, utimensat */
  25. #include <time.h>     /* mktime */
  26. #include <unistd.h>   /* getopt, opt*, close */
  27. #ifdef HAS_GETOPT_LONG
  28. #include <getopt.h>
  29. #endif
  31. const char *argv0 = "touch";
  33. // [[CC]YY]MMDDhhmm[.SS]
  34. static struct timespec
  35. opt_t_parse(char *arg, const char **errstr)
  36. {
  37. 	struct timespec res = {.tv_sec = 0, .tv_nsec = 0};
  38. 	struct tm tm = {
  39. 	    .tm_year = 0,
  40. 	    .tm_mon = 0,
  41. 	    .tm_mday = 0,
  42. 	    .tm_hour = 0,
  43. 	    .tm_min = 0,
  44. 	    .tm_sec = 0,
  45. 	    .tm_isdst = -1, // unknown if DST is in effect
  46. 	};
  48. 	size_t len = strlen(arg);
  50. 	char *secs = strrchr(arg, '.');
  51. 	if(secs != NULL)
  52. 	{
  53. 		if(&arg[len - 3] != secs)
  54. 		{
  55. 			*errstr = "Wrong location of second separator";
  56. 			return res;
  57. 		}
  59. 		secs[0] = 0;
  60. 		secs++;
  61. 		len -= 3;
  63. 		char *s = strptime(secs, "%S", &tm);
  64. 		if(s == NULL)
  65. 		{
  66. 			*errstr = strerror(errno);
  67. 			errno = 0;
  68. 			return res;
  69. 		}
  70. 		if(s[0] != 0)
  71. 		{
  72. 			*errstr = "Extraneous character in seconds";
  73. 			return res;
  74. 		}
  75. 	}
  77. 	const char *fmt = NULL;
  79. 	switch(len)
  80. 	{
  81. 	case 8:
  82. 		fmt = "%m%d%H%M"; // MMDDhhmm
  83. 		break;
  84. 	case 10:
  85. 		fmt = "%y%m%d%H%M"; // YYMMDDhhmm
  86. 		break;
  87. 	case 12:
  88. 		fmt = "%Y%m%d%H%M"; // CCYYMMDDhhmm
  89. 		break;
  90. 	default:
  91. 		*errstr = "Invalid datetime";
  92. 		return res;
  93. 	}
  94. 	assert(fmt != NULL);
  96. 	char *dt = strptime(arg, fmt, &tm);
  97. 	if(dt == NULL)
  98. 	{
  99. 		*errstr = strerror(errno);
  100. 		errno = 0;
  101. 		return res;
  102. 	}
  103. 	if(dt[0] != 0)
  104. 	{
  105. 		*errstr = "Extraneous character in datetime";
  106. 		return res;
  107. 	}
  109. 	res.tv_sec = mktime(&tm);
  110. 	if(res.tv_sec == (time_t)-1)
  111. 	{
  112. 		*errstr = strerror(errno);
  113. 		errno = 0;
  114. 		return res;
  115. 	}
  117. 	// As observed on FreeBSD 14.0, non-errorneous mktime can still end up setting errno
  118. 	// cf. https://builds.sr.ht/~lanodan/job/1181509
  119. 	errno = 0;
  121. 	return res;
  122. }
  124. int
  125. main(int argc, char *argv[])
  126. {
  127. 	bool ch_atime = false, ch_mtime = false;
  128. 	char *ref_file = NULL;
  129. 	struct timespec times[2] = {
  130. 	    {.tv_sec = 0, .tv_nsec = UTIME_OMIT}, // access
  131. 	    {.tv_sec = 0, .tv_nsec = UTIME_OMIT}  // modification
  132. 	};
  133. 	struct timespec target = {0, UTIME_NOW};
  134. 	int open_flags = O_WRONLY | O_CREAT | O_NOCTTY;
  135. 	int utimensat_flags = 0;
  137. #ifdef HAS_GETOPT_LONG
  138. 	// Strictly for GNUisms compatibility so no long-only options
  139. 	// clang-format off
  140. 	static struct option opts[] = {
  141. 		{"no-create", no_argument, NULL, 'c'},
  142. 		{"date", required_argument, NULL, 'd'},
  143. 		{"no-dereference", no_argument, NULL, 'h'},
  144. 		{"reference", required_argument, NULL, 'r'},
  145. 		{0, 0, 0, 0},
  146. 	};
  147. 	// clang-format on
  149. 	// Need + as first character to get POSIX-style option parsing
  150. 	for(int c = -1; (c = getopt_long(argc, argv, "+:acfhmr:t:d:", opts, NULL)) != -1;)
  151. #else
  152. 	for(int c = -1; (c = getopt_nolong(argc, argv, ":acfhmr:t:d:")) != -1;)
  153. #endif
  154. 	{
  155. 		const char *errstr = NULL;
  157. 		switch(c)
  158. 		{
  159. 		case 'a':
  160. 			ch_atime = true;
  161. 			break;
  162. 		case 'c':
  163. 			FIELD_CLR(open_flags, O_CREAT);
  164. 			break;
  165. 		case 'f':
  166. 			/* Legacy from BSD, ignored
  167. 			 *
  168. 			 * As of 2024-12-05:
  169. 			 *
  170. 			 * coreutils: Ignored since first commit in 1992
  171. 			 * OpenBSD: Ignored since OpenBSD 3.8 (commit in 2005)
  172. 			 * NetBSD: Ignored since NetBSD 6.0 (commit in 2011)
  173. 			 * FreeBSD: Ignored since FreeBSD 10 (commit in 2012)
  174. 			 * BusyBox: Ignored (and not documented)
  175. 			 * illumos: Ignored in SystemV emulation, supported otherwise
  176. 			 */
  177. 			break;
  178. 		case 'h':
  179. 			FIELD_SET(open_flags, O_NOFOLLOW);
  180. 			FIELD_SET(utimensat_flags, AT_SYMLINK_NOFOLLOW);
  181. 			break;
  182. 		case 'm':
  183. 			ch_mtime = true;
  184. 			break;
  185. 		case 'r':
  186. 			ref_file = optarg;
  187. 			break;
  188. 		case 't':
  189. 			target = opt_t_parse(optarg, &errstr);
  190. 			if(errstr != NULL)
  191. 			{
  192. 				fprintf(stderr, "touch: error: opt_t_parse(\"%s\", …): %s\n", optarg, errstr);
  193. 				return 1;
  194. 			}
  195. 			break;
  196. 		case 'd':
  197. 		{
  199. 			char *s = datetime_parse(optarg, &target.tv_sec, &target.tv_nsec, &errstr);
  200. 			if(errstr != NULL)
  201. 			{
  202. 				fprintf(stderr, "touch: error: datetime_parse(\"%s\", …): %s\n", optarg, errstr);
  203. 				return 1;
  204. 			}
  205. 			if(s == NULL)
  206. 			{
  207. 				fprintf(stderr, "touch: error: datetime_parse(\"%s\", …) returned NULL\n", optarg);
  208. 				return 1;
  209. 			}
  210. 			break;
  211. 		}
  212. 		case ':':
  213. 			fprintf(stderr, "touch: error: Missing operand for option: '-%c'\n", optopt);
  214. 			return 1;
  215. 		case '?':
  216. 			GETOPT_UNKNOWN_OPT
  217. 			return 1;
  218. 		}
  219. 	}
  221. 	argc -= optind;
  222. 	argv += optind;
  224. 	// When neither -a nor -m are specified, change both
  225. 	if(!ch_atime && !ch_mtime)
  226. 	{
  227. 		ch_atime = true;
  228. 		ch_mtime = true;
  229. 	}
  231. 	if(ref_file == NULL)
  232. 	{
  233. 		if(ch_atime) times[0] = target;
  234. 		if(ch_mtime) times[1] = target;
  235. 	}
  236. 	else
  237. 	{
  238. 		struct stat ref;
  240. 		if(stat(ref_file, &ref) != 0)
  241. 		{
  242. 			fprintf(stderr,
  243. 			        "touch: error: Failed getting status of file '%s': %s\n",
  244. 			        ref_file,
  245. 			        strerror(errno));
  246. 			return 1;
  247. 		}
  249. 		if(ch_atime)
  250. 		{
  251. 			times[0] = ref.st_atim;
  252. 		}
  253. 		if(ch_mtime)
  254. 		{
  255. 			times[1] = ref.st_mtim;
  256. 		}
  257. 	}
  259. 	for(int i = 0; i < argc; i++)
  260. 	{
  261. 		const char *file = argv[i];
  262. 		int fd = open(file, open_flags, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
  263. 		if(fd == -1)
  264. 		{
  265. 			/* BSD nonsense */
  266. #ifdef EMLINK
  267. 			if(errno == EMLINK) errno = ELOOP;
  268. #endif
  269. #ifdef EFTYPE
  270. 			if(errno == EFTYPE) errno = ELOOP;
  271. #endif
  273. 			if(errno == EISDIR || (errno == ELOOP && FIELD_MATCH(open_flags, O_NOFOLLOW)))
  274. 			{
  275. 				if(utimensat(AT_FDCWD, file, times, utimensat_flags) != 0)
  276. 				{
  277. 					fprintf(stderr,
  278. 					        "touch: error: Failed setting new times on file '%s': %s\n",
  279. 					        file,
  280. 					        strerror(errno));
  281. 					return 1;
  282. 				}
  284. 				continue;
  285. 			}
  287. 			if(errno != ENOENT || FIELD_MATCH(open_flags, O_CREAT))
  288. 				fprintf(stderr, "touch: error: Failed opening file '%s': %s\n", file, strerror(errno));
  290. 			return 1;
  291. 		}
  293. 		if(futimens(fd, times) != 0)
  294. 		{
  295. 			fprintf(stderr,
  296. 			        "touch: error: Failed setting new times on file '%s': %s\n",
  297. 			        file,
  298. 			        strerror(errno));
  299. 			return 1;
  300. 		}
  302. 		if(close(fd) != 0)
  303. 		{
  304. 			fprintf(stderr,
  305. 			        "touch: error: Failed closing file-descriptor for file '%s': %s\n",
  306. 			        file,
  307. 			        strerror(errno));
  308. 			return 1;
  309. 		}
  310. 	}
  312. 	return 0;
  313. }