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utils-std

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

touch.c (6455B)

    

  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 <stdlib.h>   /* exit, EXIT_FAILURE */
  18. #include <string.h>   /* strrchr, strlen */
  19. #include <sys/stat.h> /* futimens, stat, utimensat */
  20. #include <time.h>     /* mktime */
  21. #include <unistd.h>   /* getopt, opt*, close */
  23. // [[CC]YY]MMDDhhmm[.SS]
  24. static struct timespec
  25. opt_t_parse(char *arg, const char **errstr)
  26. {
  27. 	struct timespec res = {.tv_sec = 0, .tv_nsec = 0};
  28. 	struct tm tm = {
  29. 	    .tm_year = 0,
  30. 	    .tm_mon = 0,
  31. 	    .tm_mday = 0,
  32. 	    .tm_hour = 0,
  33. 	    .tm_min = 0,
  34. 	    .tm_sec = 0,
  35. 	    .tm_isdst = -1, // unknown if DST is in effect
  36. 	};
  38. 	size_t len = strlen(arg);
  40. 	char *secs = strrchr(arg, '.');
  41. 	if(secs != NULL)
  42. 	{
  43. 		if(arg[len - 3] != '.')
  44. 		{
  45. 			*errstr = "Wrong location of second separator";
  46. 			return res;
  47. 		}
  49. 		secs[0] = 0;
  50. 		secs++;
  51. 		len -= 3;
  53. 		char *s = strptime(secs, "%S", &tm);
  54. 		if(s == NULL)
  55. 		{
  56. 			*errstr = strerror(errno);
  57. 			errno = 0;
  58. 			return res;
  59. 		}
  60. 		if(s[0] != 0)
  61. 		{
  62. 			*errstr = "Extraneous character in seconds";
  63. 			return res;
  64. 		}
  65. 	}
  67. 	const char *fmt = NULL;
  69. 	switch(len)
  70. 	{
  71. 	case 8:
  72. 		fmt = "%m%d%H%M"; // MMDDhhmm
  73. 		break;
  74. 	case 10:
  75. 		fmt = "%y%m%d%H%M"; // YYMMDDhhmm
  76. 		break;
  77. 	case 12:
  78. 		fmt = "%Y%m%d%H%M"; // CCYYMMDDhhmm
  79. 		break;
  80. 	default:
  81. 		*errstr = "Invalid datetime";
  82. 		return res;
  83. 	}
  84. 	assert(fmt != NULL);
  86. 	char *dt = strptime(arg, fmt, &tm);
  87. 	if(dt == NULL)
  88. 	{
  89. 		*errstr = strerror(errno);
  90. 		errno = 0;
  91. 		return res;
  92. 	}
  93. 	if(dt[0] != 0)
  94. 	{
  95. 		*errstr = "Extraneous character in datetime";
  96. 		return res;
  97. 	}
  99. 	res.tv_sec = mktime(&tm);
  100. 	if(res.tv_sec == (time_t)-1)
  101. 	{
  102. 		*errstr = strerror(errno);
  103. 		errno = 0;
  104. 		return res;
  105. 	}
  107. 	// As observed on FreeBSD 14.0, non-errorneous mktime can still end up setting errno
  108. 	// cf. https://builds.sr.ht/~lanodan/job/1181509
  109. 	errno = 0;
  111. 	return res;
  112. }
  114. int
  115. main(int argc, char *argv[])
  116. {
  117. 	bool ch_atime = false, ch_mtime = false;
  118. 	char *ref_file = NULL;
  119. 	struct timespec times[2] = {
  120. 	    {.tv_sec = 0, .tv_nsec = UTIME_OMIT}, // access
  121. 	    {.tv_sec = 0, .tv_nsec = UTIME_OMIT}  // modification
  122. 	};
  123. 	struct timespec target = {0, UTIME_NOW};
  124. 	int open_flags = O_WRONLY | O_CREAT | O_NOCTTY;
  125. 	int utimensat_flags = 0;
  127. 	int c = 0;
  128. 	while((c = getopt(argc, argv, ":acfhmr:t:d:")) != -1)
  129. 	{
  130. 		const char *errstr = NULL;
  132. 		switch(c)
  133. 		{
  134. 		case 'a':
  135. 			ch_atime = true;
  136. 			break;
  137. 		case 'c':
  138. 			FIELD_CLR(open_flags, O_CREAT);
  139. 			break;
  140. 		case 'f':
  141. 			/* Legacy from BSD, ignored
  142. 			 *
  143. 			 * As of 2024-12-05:
  144. 			 *
  145. 			 * coreutils: Ignored since first commit in 1992
  146. 			 * OpenBSD: Ignored since OpenBSD 3.8 (commit in 2005)
  147. 			 * NetBSD: Ignored since NetBSD 6.0 (commit in 2011)
  148. 			 * FreeBSD: Ignored since FreeBSD 10 (commit in 2012)
  149. 			 * BusyBox: Ignored (and not documented)
  150. 			 * illumos: Ignored in SystemV emulation, supported otherwise
  151. 			 */
  152. 			break;
  153. 		case 'h':
  154. 			FIELD_SET(open_flags, O_NOFOLLOW);
  155. 			FIELD_SET(utimensat_flags, AT_SYMLINK_NOFOLLOW);
  156. 			break;
  157. 		case 'm':
  158. 			ch_mtime = true;
  159. 			break;
  160. 		case 'r':
  161. 			ref_file = optarg;
  162. 			break;
  163. 		case 't':
  164. 			target = opt_t_parse(optarg, &errstr);
  165. 			if(errstr != NULL)
  166. 			{
  167. 				fprintf(stderr, "touch: error: opt_t_parse(\"%s\", …): %s\n", optarg, errstr);
  168. 				exit(EXIT_FAILURE);
  169. 			}
  170. 			break;
  171. 		case 'd':
  172. 		{
  173. 			long nsec = 0;
  174. 			struct tm iso_res = {
  175. 			    .tm_year = 0,
  176. 			    .tm_mon = 0,
  177. 			    .tm_mday = 0,
  178. 			    .tm_hour = 0,
  179. 			    .tm_min = 0,
  180. 			    .tm_sec = 0,
  181. 			    .tm_isdst = -1, // unknown if DST is in effect
  182. 			    .tm_gmtoff = 0,
  183. 			    .tm_zone = NULL,
  184. 			};
  185. 			char *s = iso_parse(optarg, &iso_res, &nsec, &errstr);
  186. 			if(errstr != NULL)
  187. 			{
  188. 				fprintf(stderr, "touch: error: iso_parse(\"%s\", …): %s\n", optarg, errstr);
  189. 				exit(EXIT_FAILURE);
  190. 			}
  191. 			if(s == NULL)
  192. 			{
  193. 				fprintf(stderr, "touch: error: iso_parse(\"%s\", …) returned NULL\n", optarg);
  194. 				exit(EXIT_FAILURE);
  195. 			}
  197. 			target.tv_sec = mktime_tz(&iso_res);
  198. 			target.tv_nsec = nsec;
  199. 			if(target.tv_sec == (time_t)-1)
  200. 			{
  201. 				fprintf(stderr, "touch: error: mktime: %s\n", strerror(errno));
  202. 				exit(EXIT_FAILURE);
  203. 			}
  204. 			errno = 0;
  205. 			break;
  206. 		}
  207. 		case ':':
  208. 			fprintf(stderr, "touch: error: Missing operand for option: '-%c'\n", optopt);
  209. 			return 1;
  210. 		case '?':
  211. 			fprintf(stderr, "touch: error: Unrecognised option: '-%c'\n", optopt);
  212. 			return 1;
  213. 		}
  214. 	}
  216. 	argc -= optind;
  217. 	argv += optind;
  219. 	// When neither -a nor -m are specified, change both
  220. 	if(!ch_atime && !ch_mtime)
  221. 	{
  222. 		ch_atime = true;
  223. 		ch_mtime = true;
  224. 	}
  226. 	if(ref_file == NULL)
  227. 	{
  228. 		if(ch_atime) times[0] = target;
  229. 		if(ch_mtime) times[1] = target;
  230. 	}
  231. 	else
  232. 	{
  233. 		struct stat ref;
  235. 		if(stat(ref_file, &ref) != 0)
  236. 		{
  237. 			fprintf(stderr,
  238. 			        "touch: error: Failed getting status of file '%s': %s\n",
  239. 			        ref_file,
  240. 			        strerror(errno));
  241. 			return 1;
  242. 		}
  244. 		if(ch_atime)
  245. 		{
  246. 			times[0] = ref.st_atim;
  247. 		}
  248. 		if(ch_mtime)
  249. 		{
  250. 			times[1] = ref.st_mtim;
  251. 		}
  252. 	}
  254. 	for(int i = 0; i < argc; i++)
  255. 	{
  256. 		const char *file = argv[i];
  257. 		int fd = open(file, open_flags, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
  258. 		if(fd == -1)
  259. 		{
  260. 			if(errno == EISDIR)
  261. 			{
  262. 				if(utimensat(AT_FDCWD, file, times, utimensat_flags) != 0)
  263. 				{
  264. 					fprintf(stderr,
  265. 					        "touch: error: Failed setting new times on directory '%s': %s\n",
  266. 					        file,
  267. 					        strerror(errno));
  268. 					return 1;
  269. 				}
  271. 				return 0;
  272. 			}
  274. 			if(errno != ENOENT || FIELD_MATCH(open_flags, O_CREAT))
  275. 				fprintf(stderr, "touch: error: Failed opening file '%s': %s\n", file, strerror(errno));
  277. 			return 1;
  278. 		}
  280. 		if(futimens(fd, times) != 0)
  281. 		{
  282. 			fprintf(stderr,
  283. 			        "touch: error: Failed setting new times on file '%s': %s\n",
  284. 			        file,
  285. 			        strerror(errno));
  286. 			return 1;
  287. 		}
  289. 		if(close(fd) != 0)
  290. 		{
  291. 			fprintf(stderr,
  292. 			        "touch: error: Failed closing file-descriptor for file '%s': %s\n",
  293. 			        file,
  294. 			        strerror(errno));
  295. 			return 1;
  296. 		}
  297. 	}
  299. 	return 0;
  300. }