logo

utils-std

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

pathchk.c (3058B)

    

  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 _POSIX_C_SOURCE 200809L
  7. #include <assert.h>
  8. #include <errno.h>
  9. #include <limits.h> // PATH_MAX
  10. #include <stdbool.h>
  11. #include <stdio.h>    // fprintf
  12. #include <string.h>   // strerror
  13. #include <sys/stat.h> // lstat
  14. #include <unistd.h>   // getopt
  16. // POSIX Portable Character Set
  17. // Returns 0 on success, or the first invalid character found
  18. static char
  19. str_pcs(char *str)
  20. {
  21. 	for(size_t i = 0; i < strlen(str); i++)
  22. 	{
  23. 		char c = str[i];
  24. 		if(c >= 0x07 && c <= 0x0D) continue;
  25. 		if(c >= 0x20 && c <= 0x7E) continue;
  27. 		return c;
  28. 	}
  30. 	return 0;
  31. }
  33. static void
  34. usage(void)
  35. {
  36. 	fprintf(stderr, "Usage: pathchk [-p] [-P] pathname...\n");
  37. }
  39. int
  40. main(int argc, char *argv[])
  41. {
  42. 	bool opt_P = false, opt_p = false;
  43. 	size_t path_max = PATH_MAX - 1;
  44. 	size_t name_max = NAME_MAX;
  46. 	int c = -1;
  47. 	while((c = getopt(argc, argv, ":pP")) != -1)
  48. 	{
  49. 		switch(c)
  50. 		{
  51. 		case 'P':
  52. 			opt_P = true;
  53. 			break;
  54. 		case 'p':
  55. 			opt_p = true;
  56. 			path_max = _POSIX_PATH_MAX - 1;
  57. 			name_max = _POSIX_NAME_MAX;
  58. 			break;
  59. 		case ':':
  60. 			fprintf(stderr, "realpath: Error: Missing operand for option: '-%c'\n", optopt);
  61. 			usage();
  62. 			return 1;
  63. 		case '?':
  64. 			fprintf(stderr, "realpath: Error: Unrecognised option: '-%c'\n", optopt);
  65. 			usage();
  66. 			return 1;
  67. 		}
  68. 	}
  70. 	argv += optind;
  71. 	argc -= optind;
  73. 	if(argc != 1)
  74. 	{
  75. 		usage();
  76. 		return 1;
  77. 	}
  79. 	int err = 0;
  81. 	for(int i = 0; i < argc; i++)
  82. 	{
  83. 		char *path = argv[i];
  84. 		size_t len = strlen(path);
  86. 		if(opt_P && len == 0)
  87. 		{
  88. 			fprintf(stderr, "pathchk: Operand number %d is empty\n", i);
  89. 			err = 1;
  90. 		}
  92. 		// PATH_MAX includes terminating NULL
  93. 		if(len > path_max)
  94. 		{
  95. 			fprintf(stderr,
  96. 			        "pathchk: Path (%zd octets) is over the maximum size (%zd octets): %s\n",
  97. 			        len,
  98. 			        path_max,
  99. 			        path);
  100. 			err = 1;
  101. 		}
  103. 		char *p = strtok(path, "/");
  104. 		do
  105. 		{
  106. 			if(p == NULL || p[0] == 0) break;
  107. 			if(p[0] == '-' && opt_P)
  108. 			{
  109. 				fprintf(stderr, "pathchk: Path component starts with an hyphen: %s\n", p);
  110. 				err = 1;
  111. 			}
  113. 			// NAME_MAX doesn't includes terminating NULL
  114. 			size_t name_len = strlen(p);
  115. 			if(name_len > name_max)
  116. 			{
  117. 				fprintf(stderr,
  118. 				        "pathchk: Path component (%zd octets) is over the maximum size (%zd octets): %s\n",
  119. 				        name_len,
  120. 				        name_max,
  121. 				        p);
  122. 				err = 1;
  123. 			}
  124. 		} while((p = strtok(NULL, "/")) != NULL);
  126. 		if(!opt_p)
  127. 		{
  128. 			assert(errno == 0);
  129. 			if(access(path, F_OK) < 0 && errno != ENOENT)
  130. 			{
  131. 				fprintf(stderr,
  132. 				        "pathchk: Error while checking '%s' against filesystem: %s\n",
  133. 				        path,
  134. 				        strerror(errno));
  135. 				errno = 0;
  136. 				err = 1;
  137. 			}
  138. 		}
  139. 		else
  140. 		{
  141. 			char c_pcs = str_pcs(path);
  142. 			if(c_pcs != 0)
  143. 			{
  144. 				fprintf(stderr,
  145. 				        "pathchk: Error non-portable character '%c' (0x%02x) found in: %s\n",
  146. 				        c_pcs,
  147. 				        c_pcs,
  148. 				        path);
  149. 				err = 1;
  150. 			}
  151. 		}
  152. 	}
  154. 	return err;
  155. }