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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/getopt_nolong.h"
  11. #include "../lib/iso_parse.h" /* iso_parse */
  13. #include <assert.h>
  14. #include <errno.h>    /* errno */
  15. #include <fcntl.h>    /* open */
  16. #include <stdbool.h>  /* bool */
  17. #include <stdio.h>    /* perror */
  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. const char *argv0 = "touch";
  25. // [[CC]YY]MMDDhhmm[.SS]
  26. static struct timespec
  27. opt_t_parse(char *arg, const char **errstr)
  28. {
  29. 	struct timespec res = {.tv_sec = 0, .tv_nsec = 0};
  30. 	struct tm tm = {
  31. 	    .tm_year = 0,
  32. 	    .tm_mon = 0,
  33. 	    .tm_mday = 0,
  34. 	    .tm_hour = 0,
  35. 	    .tm_min = 0,
  36. 	    .tm_sec = 0,
  37. 	    .tm_isdst = -1, // unknown if DST is in effect
  38. 	};
  40. 	size_t len = strlen(arg);
  42. 	char *secs = strrchr(arg, '.');
  43. 	if(secs != NULL)
  44. 	{
  45. 		if(arg[len - 3] != '.')
  46. 		{
  47. 			*errstr = "Wrong location of second separator";
  48. 			return res;
  49. 		}
  51. 		secs[0] = 0;
  52. 		secs++;
  53. 		len -= 3;
  55. 		char *s = strptime(secs, "%S", &tm);
  56. 		if(s == NULL)
  57. 		{
  58. 			*errstr = strerror(errno);
  59. 			errno = 0;
  60. 			return res;
  61. 		}
  62. 		if(s[0] != 0)
  63. 		{
  64. 			*errstr = "Extraneous character in seconds";
  65. 			return res;
  66. 		}
  67. 	}
  69. 	const char *fmt = NULL;
  71. 	switch(len)
  72. 	{
  73. 	case 8:
  74. 		fmt = "%m%d%H%M"; // MMDDhhmm
  75. 		break;
  76. 	case 10:
  77. 		fmt = "%y%m%d%H%M"; // YYMMDDhhmm
  78. 		break;
  79. 	case 12:
  80. 		fmt = "%Y%m%d%H%M"; // CCYYMMDDhhmm
  81. 		break;
  82. 	default:
  83. 		*errstr = "Invalid datetime";
  84. 		return res;
  85. 	}
  86. 	assert(fmt != NULL);
  88. 	char *dt = strptime(arg, fmt, &tm);
  89. 	if(dt == NULL)
  90. 	{
  91. 		*errstr = strerror(errno);
  92. 		errno = 0;
  93. 		return res;
  94. 	}
  95. 	if(dt[0] != 0)
  96. 	{
  97. 		*errstr = "Extraneous character in datetime";
  98. 		return res;
  99. 	}
  101. 	res.tv_sec = mktime(&tm);
  102. 	if(res.tv_sec == (time_t)-1)
  103. 	{
  104. 		*errstr = strerror(errno);
  105. 		errno = 0;
  106. 		return res;
  107. 	}
  109. 	// As observed on FreeBSD 14.0, non-errorneous mktime can still end up setting errno
  110. 	// cf. https://builds.sr.ht/~lanodan/job/1181509
  111. 	errno = 0;
  113. 	return res;
  114. }
  116. int
  117. main(int argc, char *argv[])
  118. {
  119. 	bool ch_atime = false, ch_mtime = false;
  120. 	char *ref_file = NULL;
  121. 	struct timespec times[2] = {
  122. 	    {.tv_sec = 0, .tv_nsec = UTIME_OMIT}, // access
  123. 	    {.tv_sec = 0, .tv_nsec = UTIME_OMIT}  // modification
  124. 	};
  125. 	struct timespec target = {0, UTIME_NOW};
  126. 	int open_flags = O_WRONLY | O_CREAT | O_NOCTTY;
  127. 	int utimensat_flags = 0;
  129. 	for(int c = -1; (c = getopt_nolong(argc, argv, ":acfhmr:t:d:")) != -1;)
  130. 	{
  131. 		const char *errstr = NULL;
  133. 		switch(c)
  134. 		{
  135. 		case 'a':
  136. 			ch_atime = true;
  137. 			break;
  138. 		case 'c':
  139. 			FIELD_CLR(open_flags, O_CREAT);
  140. 			break;
  141. 		case 'f':
  142. 			/* Legacy from BSD, ignored
  143. 			 *
  144. 			 * As of 2024-12-05:
  145. 			 *
  146. 			 * coreutils: Ignored since first commit in 1992
  147. 			 * OpenBSD: Ignored since OpenBSD 3.8 (commit in 2005)
  148. 			 * NetBSD: Ignored since NetBSD 6.0 (commit in 2011)
  149. 			 * FreeBSD: Ignored since FreeBSD 10 (commit in 2012)
  150. 			 * BusyBox: Ignored (and not documented)
  151. 			 * illumos: Ignored in SystemV emulation, supported otherwise
  152. 			 */
  153. 			break;
  154. 		case 'h':
  155. 			FIELD_SET(open_flags, O_NOFOLLOW);
  156. 			FIELD_SET(utimensat_flags, AT_SYMLINK_NOFOLLOW);
  157. 			break;
  158. 		case 'm':
  159. 			ch_mtime = true;
  160. 			break;
  161. 		case 'r':
  162. 			ref_file = optarg;
  163. 			break;
  164. 		case 't':
  165. 			target = opt_t_parse(optarg, &errstr);
  166. 			if(errstr != NULL)
  167. 			{
  168. 				fprintf(stderr, "touch: error: opt_t_parse(\"%s\", …): %s\n", optarg, errstr);
  169. 				return 1;
  170. 			}
  171. 			break;
  172. 		case 'd':
  173. 		{
  174. 			long nsec = 0;
  175. 			struct tm iso_res = {
  176. 			    .tm_year = 0,
  177. 			    .tm_mon = 0,
  178. 			    .tm_mday = 0,
  179. 			    .tm_hour = 0,
  180. 			    .tm_min = 0,
  181. 			    .tm_sec = 0,
  182. 			    .tm_isdst = -1, // unknown if DST is in effect
  183. 			    .tm_gmtoff = 0,
  184. 			    .tm_zone = NULL,
  185. 			};
  186. 			char *s = iso_parse(optarg, &iso_res, &nsec, &errstr);
  187. 			if(errstr != NULL)
  188. 			{
  189. 				fprintf(stderr, "touch: error: iso_parse(\"%s\", …): %s\n", optarg, errstr);
  190. 				return 1;
  191. 			}
  192. 			if(s == NULL)
  193. 			{
  194. 				fprintf(stderr, "touch: error: iso_parse(\"%s\", …) returned NULL\n", optarg);
  195. 				return 1;
  196. 			}
  198. 			target.tv_sec = mktime_tz(&iso_res);
  199. 			target.tv_nsec = nsec;
  200. 			if(target.tv_sec == (time_t)-1)
  201. 			{
  202. 				fprintf(stderr, "touch: error: mktime: %s\n", strerror(errno));
  203. 				return 1;
  204. 			}
  205. 			errno = 0;
  206. 			break;
  207. 		}
  208. 		case ':':
  209. 			fprintf(stderr, "touch: error: Missing operand for option: '-%c'\n", optopt);
  210. 			return 1;
  211. 		case '?':
  212. 			if(!got_long_opt) fprintf(stderr, "touch: error: Unrecognised option: '-%c'\n", optopt);
  213. 			return 1;
  214. 		}
  215. 	}
  217. 	argc -= optind;
  218. 	argv += optind;
  220. 	// When neither -a nor -m are specified, change both
  221. 	if(!ch_atime && !ch_mtime)
  222. 	{
  223. 		ch_atime = true;
  224. 		ch_mtime = true;
  225. 	}
  227. 	if(ref_file == NULL)
  228. 	{
  229. 		if(ch_atime) times[0] = target;
  230. 		if(ch_mtime) times[1] = target;
  231. 	}
  232. 	else
  233. 	{
  234. 		struct stat ref;
  236. 		if(stat(ref_file, &ref) != 0)
  237. 		{
  238. 			fprintf(stderr,
  239. 			        "touch: error: Failed getting status of file '%s': %s\n",
  240. 			        ref_file,
  241. 			        strerror(errno));
  242. 			return 1;
  243. 		}
  245. 		if(ch_atime)
  246. 		{
  247. 			times[0] = ref.st_atim;
  248. 		}
  249. 		if(ch_mtime)
  250. 		{
  251. 			times[1] = ref.st_mtim;
  252. 		}
  253. 	}
  255. 	for(int i = 0; i < argc; i++)
  256. 	{
  257. 		const char *file = argv[i];
  258. 		int fd = open(file, open_flags, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
  259. 		if(fd == -1)
  260. 		{
  261. 			if(errno == EISDIR)
  262. 			{
  263. 				if(utimensat(AT_FDCWD, file, times, utimensat_flags) != 0)
  264. 				{
  265. 					fprintf(stderr,
  266. 					        "touch: error: Failed setting new times on directory '%s': %s\n",
  267. 					        file,
  268. 					        strerror(errno));
  269. 					return 1;
  270. 				}
  272. 				return 0;
  273. 			}
  275. 			if(errno != ENOENT || FIELD_MATCH(open_flags, O_CREAT))
  276. 				fprintf(stderr, "touch: error: Failed opening file '%s': %s\n", file, strerror(errno));
  278. 			return 1;
  279. 		}
  281. 		if(futimens(fd, times) != 0)
  282. 		{
  283. 			fprintf(stderr,
  284. 			        "touch: error: Failed setting new times on file '%s': %s\n",
  285. 			        file,
  286. 			        strerror(errno));
  287. 			return 1;
  288. 		}
  290. 		if(close(fd) != 0)
  291. 		{
  292. 			fprintf(stderr,
  293. 			        "touch: error: Failed closing file-descriptor for file '%s': %s\n",
  294. 			        file,
  295. 			        strerror(errno));
  296. 			return 1;
  297. 		}
  298. 	}
  300. 	return 0;
  301. }