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utils-std

Collection of commonly available Unix tools

mknod.c (3060B)

    

  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
  6. #define _XOPEN_SOURCE 700 // mknod is in XSI
  8. #include "../lib/mode.h"
  10. #include <assert.h>
  11. #include <errno.h>
  12. #include <stdio.h>         // fprintf
  13. #include <stdlib.h>        // abort, exit
  14. #include <string.h>        // strerror, strrchr
  15. #include <sys/stat.h>      // mknod
  16. #include <sys/sysmacros.h> // makedev
  17. #include <unistd.h>        // getopt
  19. mode_t filemask;
  21. static void
  22. usage()
  23. {
  24. 	fprintf(stderr, "Usage: mknod [-m mode] file <b|c|u|p> [major minor]\n");
  25. }
  27. static unsigned int
  28. strtodev(char *arg)
  29. {
  30. 	char *endptr = NULL;
  31. 	assert(errno == 0);
  32. 	long dev = strtol(arg, &endptr, 0);
  33. 	if(errno != 0)
  34. 	{
  35. 		fprintf(stderr, "mknod: Failed parsing '%s' into a number: %s\n", arg, strerror(errno));
  36. 		exit(1);
  37. 	}
  38. 	if(endptr != NULL && endptr[0] != 0)
  39. 	{
  40. 		fprintf(stderr,
  41. 		        "mknod: Extraneous characters in '%s' while parsing it as a number: '%s'\n",
  42. 		        arg,
  43. 		        endptr);
  44. 		exit(1);
  45. 	}
  47. 	return (unsigned int)dev;
  48. }
  50. int
  51. main(int argc, char *argv[])
  52. {
  53. 	mode_t mode = 0666;
  55. 	const char *errstr = NULL;
  57. 	int c = -1;
  58. 	while((c = getopt(argc, argv, ":m:")) != -1)
  59. 	{
  60. 		switch(c)
  61. 		{
  62. 		case 'm':
  63. 			mode = new_mode(optarg, 0666, &errstr);
  64. 			if(errstr != NULL)
  65. 			{
  66. 				fprintf(stderr, "mknod: Failed parsing mode '%s': %s\n", optarg, errstr);
  67. 				return 1;
  68. 			}
  69. 			break;
  70. 		case ':':
  71. 			fprintf(stderr, "mknod: Error: Missing operand for option: '-%c'\n", optopt);
  72. 			usage();
  73. 			return 1;
  74. 		case '?':
  75. 			fprintf(stderr, "mknod: Error: Unrecognised option: '-%c'\n", optopt);
  76. 			usage();
  77. 			return 1;
  78. 		default:
  79. 			abort();
  80. 		}
  81. 	}
  83. 	argc -= optind;
  84. 	argv += optind;
  86. 	assert(errno == 0);
  88. 	if(argc < 2)
  89. 	{
  90. 		fprintf(stderr, "mknod: Missing operands\n");
  91. 		usage();
  92. 		return 1;
  93. 	}
  95. 	char *file = argv[0];
  96. 	char *type = argv[1];
  98. 	if(type[0] == 0 || type[1] != 0)
  99. 	{
  100. 		fprintf(stderr, "mknod: Invalid type '%s'\n", type);
  101. 		usage();
  102. 		return 1;
  103. 	}
  105. 	assert(errno == 0);
  106. 	if(type[0] == 'p')
  107. 	{
  108. 		if(mknod(file, mode | S_IFIFO, 0) != 0)
  109. 		{
  110. 			fprintf(stderr, "mknod: Failed creating FIFO at '%s': %s\n", file, strerror(errno));
  111. 			return 1;
  112. 		}
  113. 	}
  114. 	else
  115. 	{
  116. 		if(argc != 4)
  117. 		{
  118. 			fprintf(stderr, "mknod: non-FIFO device types requires major minor arguments to be given\n");
  119. 			return 1;
  120. 		}
  122. 		unsigned int maj = strtodev(argv[2]);
  123. 		unsigned int min = strtodev(argv[3]);
  125. 		char *type_name;
  126. 		switch(type[0])
  127. 		{
  128. 		case 'b':
  129. 			mode |= S_IFBLK;
  130. 			type_name = "block-special";
  131. 			break;
  132. 		case 'c':
  133. 			mode |= S_IFCHR;
  134. 			type_name = "character-special";
  135. 			break;
  136. 		case 'u':
  137. 			mode |= S_IFCHR;
  138. 			type_name = "character-special";
  139. 			break;
  140. 		default:
  141. 			fprintf(stderr, "mknod: Invalid type '%c'\n", type[0]);
  142. 			usage();
  143. 			return 1;
  144. 		}
  146. 		if(mknod(file, mode, makedev(maj, min)) != 0)
  147. 		{
  148. 			fprintf(stderr, "mknod: Failed creating %s at '%s': %s\n", type_name, file, strerror(errno));
  149. 			return 1;
  150. 		}
  151. 	}
  153. 	return 0;
  154. }