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utils-std

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

touch.c (6367B)

    

  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. #include "../lib/bitmasks.h"  /* FIELD_* */
  10. #include "../lib/iso_parse.h" /* iso_parse */
  12. #include <assert.h>
  13. #include <errno.h>    /* errno */
  14. #include <fcntl.h>    /* open */
  15. #include <stdbool.h>  /* bool */
  16. #include <stdio.h>    /* perror */
  17. #include <string.h>   /* strrchr, strlen */
  18. #include <sys/stat.h> /* futimens, stat, utimensat */
  19. #include <time.h>     /* mktime */
  20. #include <unistd.h>   /* getopt, opt*, close */
  22. // [[CC]YY]MMDDhhmm[.SS]
  23. static struct timespec
  24. opt_t_parse(char *arg, const char **errstr)
  25. {
  26. 	struct timespec res = {.tv_sec = 0, .tv_nsec = 0};
  27. 	struct tm tm = {
  28. 	    .tm_year = 0,
  29. 	    .tm_mon = 0,
  30. 	    .tm_mday = 0,
  31. 	    .tm_hour = 0,
  32. 	    .tm_min = 0,
  33. 	    .tm_sec = 0,
  34. 	    .tm_isdst = -1, // unknown if DST is in effect
  35. 	};
  37. 	size_t len = strlen(arg);
  39. 	char *secs = strrchr(arg, '.');
  40. 	if(secs != NULL)
  41. 	{
  42. 		if(arg[len - 3] != '.')
  43. 		{
  44. 			*errstr = "Wrong location of second separator";
  45. 			return res;
  46. 		}
  48. 		secs[0] = 0;
  49. 		secs++;
  50. 		len -= 3;
  52. 		char *s = strptime(secs, "%S", &tm);
  53. 		if(s == NULL)
  54. 		{
  55. 			*errstr = strerror(errno);
  56. 			errno = 0;
  57. 			return res;
  58. 		}
  59. 		if(s[0] != 0)
  60. 		{
  61. 			*errstr = "Extraneous character in seconds";
  62. 			return res;
  63. 		}
  64. 	}
  66. 	const char *fmt = NULL;
  68. 	switch(len)
  69. 	{
  70. 	case 8:
  71. 		fmt = "%m%d%H%M"; // MMDDhhmm
  72. 		break;
  73. 	case 10:
  74. 		fmt = "%y%m%d%H%M"; // YYMMDDhhmm
  75. 		break;
  76. 	case 12:
  77. 		fmt = "%Y%m%d%H%M"; // CCYYMMDDhhmm
  78. 		break;
  79. 	default:
  80. 		*errstr = "Invalid datetime";
  81. 		return res;
  82. 	}
  83. 	assert(fmt != NULL);
  85. 	char *dt = strptime(arg, fmt, &tm);
  86. 	if(dt == NULL)
  87. 	{
  88. 		*errstr = strerror(errno);
  89. 		errno = 0;
  90. 		return res;
  91. 	}
  92. 	if(dt[0] != 0)
  93. 	{
  94. 		*errstr = "Extraneous character in datetime";
  95. 		return res;
  96. 	}
  98. 	res.tv_sec = mktime(&tm);
  99. 	if(res.tv_sec == (time_t)-1)
  100. 	{
  101. 		*errstr = strerror(errno);
  102. 		errno = 0;
  103. 		return res;
  104. 	}
  106. 	// As observed on FreeBSD 14.0, non-errorneous mktime can still end up setting errno
  107. 	// cf. https://builds.sr.ht/~lanodan/job/1181509
  108. 	errno = 0;
  110. 	return res;
  111. }
  113. int
  114. main(int argc, char *argv[])
  115. {
  116. 	bool ch_atime = false, ch_mtime = false;
  117. 	char *ref_file = NULL;
  118. 	struct timespec times[2] = {
  119. 	    {.tv_sec = 0, .tv_nsec = UTIME_OMIT}, // access
  120. 	    {.tv_sec = 0, .tv_nsec = UTIME_OMIT}  // modification
  121. 	};
  122. 	struct timespec target = {0, UTIME_NOW};
  123. 	int open_flags = O_WRONLY | O_CREAT | O_NOCTTY;
  124. 	int utimensat_flags = 0;
  126. 	for(int c = -1; (c = getopt(argc, argv, ":acfhmr:t:d:")) != -1;)
  127. 	{
  128. 		const char *errstr = NULL;
  130. 		switch(c)
  131. 		{
  132. 		case 'a':
  133. 			ch_atime = true;
  134. 			break;
  135. 		case 'c':
  136. 			FIELD_CLR(open_flags, O_CREAT);
  137. 			break;
  138. 		case 'f':
  139. 			/* Legacy from BSD, ignored
  140. 			 *
  141. 			 * As of 2024-12-05:
  142. 			 *
  143. 			 * coreutils: Ignored since first commit in 1992
  144. 			 * OpenBSD: Ignored since OpenBSD 3.8 (commit in 2005)
  145. 			 * NetBSD: Ignored since NetBSD 6.0 (commit in 2011)
  146. 			 * FreeBSD: Ignored since FreeBSD 10 (commit in 2012)
  147. 			 * BusyBox: Ignored (and not documented)
  148. 			 * illumos: Ignored in SystemV emulation, supported otherwise
  149. 			 */
  150. 			break;
  151. 		case 'h':
  152. 			FIELD_SET(open_flags, O_NOFOLLOW);
  153. 			FIELD_SET(utimensat_flags, AT_SYMLINK_NOFOLLOW);
  154. 			break;
  155. 		case 'm':
  156. 			ch_mtime = true;
  157. 			break;
  158. 		case 'r':
  159. 			ref_file = optarg;
  160. 			break;
  161. 		case 't':
  162. 			target = opt_t_parse(optarg, &errstr);
  163. 			if(errstr != NULL)
  164. 			{
  165. 				fprintf(stderr, "touch: error: opt_t_parse(\"%s\", …): %s\n", optarg, errstr);
  166. 				return 1;
  167. 			}
  168. 			break;
  169. 		case 'd':
  170. 		{
  171. 			long nsec = 0;
  172. 			struct tm iso_res = {
  173. 			    .tm_year = 0,
  174. 			    .tm_mon = 0,
  175. 			    .tm_mday = 0,
  176. 			    .tm_hour = 0,
  177. 			    .tm_min = 0,
  178. 			    .tm_sec = 0,
  179. 			    .tm_isdst = -1, // unknown if DST is in effect
  180. 			    .tm_gmtoff = 0,
  181. 			    .tm_zone = NULL,
  182. 			};
  183. 			char *s = iso_parse(optarg, &iso_res, &nsec, &errstr);
  184. 			if(errstr != NULL)
  185. 			{
  186. 				fprintf(stderr, "touch: error: iso_parse(\"%s\", …): %s\n", optarg, errstr);
  187. 				return 1;
  188. 			}
  189. 			if(s == NULL)
  190. 			{
  191. 				fprintf(stderr, "touch: error: iso_parse(\"%s\", …) returned NULL\n", optarg);
  192. 				return 1;
  193. 			}
  195. 			target.tv_sec = mktime_tz(&iso_res);
  196. 			target.tv_nsec = nsec;
  197. 			if(target.tv_sec == (time_t)-1)
  198. 			{
  199. 				fprintf(stderr, "touch: error: mktime: %s\n", strerror(errno));
  200. 				return 1;
  201. 			}
  202. 			errno = 0;
  203. 			break;
  204. 		}
  205. 		case ':':
  206. 			fprintf(stderr, "touch: error: Missing operand for option: '-%c'\n", optopt);
  207. 			return 1;
  208. 		case '?':
  209. 			fprintf(stderr, "touch: error: Unrecognised option: '-%c'\n", optopt);
  210. 			return 1;
  211. 		}
  212. 	}
  214. 	argc -= optind;
  215. 	argv += optind;
  217. 	// When neither -a nor -m are specified, change both
  218. 	if(!ch_atime && !ch_mtime)
  219. 	{
  220. 		ch_atime = true;
  221. 		ch_mtime = true;
  222. 	}
  224. 	if(ref_file == NULL)
  225. 	{
  226. 		if(ch_atime) times[0] = target;
  227. 		if(ch_mtime) times[1] = target;
  228. 	}
  229. 	else
  230. 	{
  231. 		struct stat ref;
  233. 		if(stat(ref_file, &ref) != 0)
  234. 		{
  235. 			fprintf(stderr,
  236. 			        "touch: error: Failed getting status of file '%s': %s\n",
  237. 			        ref_file,
  238. 			        strerror(errno));
  239. 			return 1;
  240. 		}
  242. 		if(ch_atime)
  243. 		{
  244. 			times[0] = ref.st_atim;
  245. 		}
  246. 		if(ch_mtime)
  247. 		{
  248. 			times[1] = ref.st_mtim;
  249. 		}
  250. 	}
  252. 	for(int i = 0; i < argc; i++)
  253. 	{
  254. 		const char *file = argv[i];
  255. 		int fd = open(file, open_flags, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
  256. 		if(fd == -1)
  257. 		{
  258. 			if(errno == EISDIR)
  259. 			{
  260. 				if(utimensat(AT_FDCWD, file, times, utimensat_flags) != 0)
  261. 				{
  262. 					fprintf(stderr,
  263. 					        "touch: error: Failed setting new times on directory '%s': %s\n",
  264. 					        file,
  265. 					        strerror(errno));
  266. 					return 1;
  267. 				}
  269. 				return 0;
  270. 			}
  272. 			if(errno != ENOENT || FIELD_MATCH(open_flags, O_CREAT))
  273. 				fprintf(stderr, "touch: error: Failed opening file '%s': %s\n", file, strerror(errno));
  275. 			return 1;
  276. 		}
  278. 		if(futimens(fd, times) != 0)
  279. 		{
  280. 			fprintf(stderr,
  281. 			        "touch: error: Failed setting new times on file '%s': %s\n",
  282. 			        file,
  283. 			        strerror(errno));
  284. 			return 1;
  285. 		}
  287. 		if(close(fd) != 0)
  288. 		{
  289. 			fprintf(stderr,
  290. 			        "touch: error: Failed closing file-descriptor for file '%s': %s\n",
  291. 			        file,
  292. 			        strerror(errno));
  293. 			return 1;
  294. 		}
  295. 	}
  297. 	return 0;
  298. }