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utils-std

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

touch.c (6521B)

    

  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 "../lib/bitmasks.h"            /* FIELD_* */
  14. #include "../libutils/datetime_parse.h" /* datetime_parse */
  15. #include "../libutils/getopt_nolong.h"
  17. #include <assert.h>
  18. #include <errno.h>    /* errno */
  19. #include <fcntl.h>    /* open */
  20. #include <stdbool.h>  /* bool */
  21. #include <stdio.h>    /* perror */
  22. #include <string.h>   /* strrchr, strlen */
  23. #include <sys/stat.h> /* futimens, stat, utimensat */
  24. #include <time.h>     /* mktime */
  25. #include <unistd.h>   /* getopt, opt*, close */
  27. const char *argv0 = "touch";
  29. // [[CC]YY]MMDDhhmm[.SS]
  30. static struct timespec
  31. opt_t_parse(char *arg, const char **errstr)
  32. {
  33. 	struct timespec res = {.tv_sec = 0, .tv_nsec = 0};
  34. 	struct tm tm = {
  35. 	    .tm_year = 0,
  36. 	    .tm_mon = 0,
  37. 	    .tm_mday = 0,
  38. 	    .tm_hour = 0,
  39. 	    .tm_min = 0,
  40. 	    .tm_sec = 0,
  41. 	    .tm_isdst = -1, // unknown if DST is in effect
  42. 	};
  44. 	size_t len = strlen(arg);
  46. 	char *secs = strrchr(arg, '.');
  47. 	if(secs != NULL)
  48. 	{
  49. 		if(&arg[len - 3] != secs)
  50. 		{
  51. 			*errstr = "Wrong location of second separator";
  52. 			return res;
  53. 		}
  55. 		secs[0] = 0;
  56. 		secs++;
  57. 		len -= 3;
  59. 		char *s = strptime(secs, "%S", &tm);
  60. 		if(s == NULL)
  61. 		{
  62. 			*errstr = strerror(errno);
  63. 			errno = 0;
  64. 			return res;
  65. 		}
  66. 		if(s[0] != 0)
  67. 		{
  68. 			*errstr = "Extraneous character in seconds";
  69. 			return res;
  70. 		}
  71. 	}
  73. 	const char *fmt = NULL;
  75. 	switch(len)
  76. 	{
  77. 	case 8:
  78. 		fmt = "%m%d%H%M"; // MMDDhhmm
  79. 		break;
  80. 	case 10:
  81. 		fmt = "%y%m%d%H%M"; // YYMMDDhhmm
  82. 		break;
  83. 	case 12:
  84. 		fmt = "%Y%m%d%H%M"; // CCYYMMDDhhmm
  85. 		break;
  86. 	default:
  87. 		*errstr = "Invalid datetime";
  88. 		return res;
  89. 	}
  90. 	assert(fmt != NULL);
  92. 	char *dt = strptime(arg, fmt, &tm);
  93. 	if(dt == NULL)
  94. 	{
  95. 		*errstr = strerror(errno);
  96. 		errno = 0;
  97. 		return res;
  98. 	}
  99. 	if(dt[0] != 0)
  100. 	{
  101. 		*errstr = "Extraneous character in datetime";
  102. 		return res;
  103. 	}
  105. 	res.tv_sec = mktime(&tm);
  106. 	if(res.tv_sec == (time_t)-1)
  107. 	{
  108. 		*errstr = strerror(errno);
  109. 		errno = 0;
  110. 		return res;
  111. 	}
  113. 	// As observed on FreeBSD 14.0, non-errorneous mktime can still end up setting errno
  114. 	// cf. https://builds.sr.ht/~lanodan/job/1181509
  115. 	errno = 0;
  117. 	return res;
  118. }
  120. int
  121. main(int argc, char *argv[])
  122. {
  123. 	bool ch_atime = false, ch_mtime = false;
  124. 	char *ref_file = NULL;
  125. 	struct timespec times[2] = {
  126. 	    {.tv_sec = 0, .tv_nsec = UTIME_OMIT}, // access
  127. 	    {.tv_sec = 0, .tv_nsec = UTIME_OMIT}  // modification
  128. 	};
  129. 	struct timespec target = {0, UTIME_NOW};
  130. 	int open_flags = O_WRONLY | O_CREAT | O_NOCTTY;
  131. 	int utimensat_flags = 0;
  133. 	for(int c = -1; (c = getopt_nolong(argc, argv, ":acfhmr:t:d:")) != -1;)
  134. 	{
  135. 		const char *errstr = NULL;
  137. 		switch(c)
  138. 		{
  139. 		case 'a':
  140. 			ch_atime = true;
  141. 			break;
  142. 		case 'c':
  143. 			FIELD_CLR(open_flags, O_CREAT);
  144. 			break;
  145. 		case 'f':
  146. 			/* Legacy from BSD, ignored
  147. 			 *
  148. 			 * As of 2024-12-05:
  149. 			 *
  150. 			 * coreutils: Ignored since first commit in 1992
  151. 			 * OpenBSD: Ignored since OpenBSD 3.8 (commit in 2005)
  152. 			 * NetBSD: Ignored since NetBSD 6.0 (commit in 2011)
  153. 			 * FreeBSD: Ignored since FreeBSD 10 (commit in 2012)
  154. 			 * BusyBox: Ignored (and not documented)
  155. 			 * illumos: Ignored in SystemV emulation, supported otherwise
  156. 			 */
  157. 			break;
  158. 		case 'h':
  159. 			FIELD_SET(open_flags, O_NOFOLLOW);
  160. 			FIELD_SET(utimensat_flags, AT_SYMLINK_NOFOLLOW);
  161. 			break;
  162. 		case 'm':
  163. 			ch_mtime = true;
  164. 			break;
  165. 		case 'r':
  166. 			ref_file = optarg;
  167. 			break;
  168. 		case 't':
  169. 			target = opt_t_parse(optarg, &errstr);
  170. 			if(errstr != NULL)
  171. 			{
  172. 				fprintf(stderr, "touch: error: opt_t_parse(\"%s\", …): %s\n", optarg, errstr);
  173. 				return 1;
  174. 			}
  175. 			break;
  176. 		case 'd':
  177. 		{
  178. 			long nsec = 0;
  179. 			struct tm iso_res = {
  180. 			    .tm_year = 0,
  181. 			    .tm_mon = 0,
  182. 			    .tm_mday = 0,
  183. 			    .tm_hour = 0,
  184. 			    .tm_min = 0,
  185. 			    .tm_sec = 0,
  186. 			    .tm_isdst = -1, // unknown if DST is in effect
  187. 			    .tm_gmtoff = 0,
  188. 			    .tm_zone = NULL,
  189. 			};
  190. 			char *s = datetime_parse(optarg, &iso_res, &nsec, &errstr);
  191. 			if(errstr != NULL)
  192. 			{
  193. 				fprintf(stderr, "touch: error: datetime_parse(\"%s\", …): %s\n", optarg, errstr);
  194. 				return 1;
  195. 			}
  196. 			if(s == NULL)
  197. 			{
  198. 				fprintf(stderr, "touch: error: datetime_parse(\"%s\", …) returned NULL\n", optarg);
  199. 				return 1;
  200. 			}
  202. 			target.tv_sec = mktime_tz(&iso_res);
  203. 			target.tv_nsec = nsec;
  204. 			if(target.tv_sec == (time_t)-1)
  205. 			{
  206. 				fprintf(stderr, "touch: error: mktime: %s\n", strerror(errno));
  207. 				return 1;
  208. 			}
  209. 			errno = 0;
  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. 			if(errno == EISDIR)
  266. 			{
  267. 				if(utimensat(AT_FDCWD, file, times, utimensat_flags) != 0)
  268. 				{
  269. 					fprintf(stderr,
  270. 					        "touch: error: Failed setting new times on directory '%s': %s\n",
  271. 					        file,
  272. 					        strerror(errno));
  273. 					return 1;
  274. 				}
  276. 				continue;
  277. 			}
  279. 			if(errno != ENOENT || FIELD_MATCH(open_flags, O_CREAT))
  280. 				fprintf(stderr, "touch: error: Failed opening file '%s': %s\n", file, strerror(errno));
  282. 			return 1;
  283. 		}
  285. 		if(futimens(fd, times) != 0)
  286. 		{
  287. 			fprintf(stderr,
  288. 			        "touch: error: Failed setting new times on file '%s': %s\n",
  289. 			        file,
  290. 			        strerror(errno));
  291. 			return 1;
  292. 		}
  294. 		if(close(fd) != 0)
  295. 		{
  296. 			fprintf(stderr,
  297. 			        "touch: error: Failed closing file-descriptor for file '%s': %s\n",
  298. 			        file,
  299. 			        strerror(errno));
  300. 			return 1;
  301. 		}
  302. 	}
  304. 	return 0;
  305. }