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utils-std

Collection of commonly available Unix tools

uname.c (2307B)

    

  1. // utils-std: Collection of commonly available Unix tools
  2. // SPDX-FileCopyrightText: 2017-2022 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
  3. // SPDX-License-Identifier: MPL-2.0
  5. #define _POSIX_C_SOURCE 200809L
  6. #include "../lib/bitmasks.h"
  8. #include <errno.h>
  9. #include <stdio.h>       // printf
  10. #include <stdlib.h>      // exit, abort
  11. #include <string.h>      // strerror
  12. #include <sys/utsname.h> // uname
  13. #include <unistd.h>      // getopt
  15. enum uname_names
  16. {
  17. 	CMD_UNAME_SYSNAME = 1 << 1,
  18. 	CMD_UNAME_NODENAME = 1 << 2,
  19. 	CMD_UNAME_RELEASE = 1 << 3,
  20. 	CMD_UNAME_VERSION = 1 << 4,
  21. 	CMD_UNAME_MACHINE = 1 << 5,
  22. 	CMD_UNAME_ALL = CMD_UNAME_SYSNAME | CMD_UNAME_NODENAME | CMD_UNAME_RELEASE | CMD_UNAME_VERSION |
  23. 	                CMD_UNAME_MACHINE,
  24. };
  26. const char *fmt = "%s";
  27. enum uname_names names = 0;
  29. static void
  30. maybe_print_name(enum uname_names key, char *value)
  31. {
  32. 	if(FIELD_MATCH(names, key))
  33. 	{
  34. 		if(printf(fmt, value) < 0)
  35. 		{
  36. 			fprintf(stderr, "uname: Write Error: %s", strerror(errno));
  37. 			exit(1);
  38. 		}
  39. 		fmt = " %s";
  40. 	}
  41. }
  43. static void
  44. usage()
  45. {
  46. 	fprintf(stderr, "Usage: uname [-amnrsv]\n");
  47. }
  49. int
  50. main(int argc, char *argv[])
  51. {
  52. 	int c = -1;
  53. 	while((c = getopt(argc, argv, ":amnrsv")) != -1)
  54. 	{
  55. 		switch(c)
  56. 		{
  57. 		case 'a':
  58. 			names = CMD_UNAME_ALL;
  59. 			break;
  60. 		case 'm':
  61. 			names |= CMD_UNAME_MACHINE;
  62. 			break;
  63. 		case 'n':
  64. 			names |= CMD_UNAME_NODENAME;
  65. 			break;
  66. 		case 'r':
  67. 			names |= CMD_UNAME_RELEASE;
  68. 			break;
  69. 		case 's':
  70. 			names |= CMD_UNAME_SYSNAME;
  71. 			break;
  72. 		case 'v':
  73. 			names |= CMD_UNAME_VERSION;
  74. 			break;
  75. 		case ':':
  76. 			fprintf(stderr, "uname: Error: Missing operand for option: '-%c'\n", optopt);
  77. 			usage();
  78. 			return 1;
  79. 		case '?':
  80. 			fprintf(stderr, "uname: Error: Unrecognised option: '-%c'\n", optopt);
  81. 			usage();
  82. 			return 1;
  83. 		default:
  84. 			abort();
  85. 		}
  86. 	}
  87. 	if(names == 0) names |= CMD_UNAME_SYSNAME;
  89. 	struct utsname name;
  90. 	if(uname(&name) != 0)
  91. 	{
  92. 		fprintf(
  93. 		    stderr, "uname: Failed getting current system names via uname(): %s\n", strerror(errno));
  94. 		return 1;
  95. 	}
  97. 	maybe_print_name(CMD_UNAME_SYSNAME, name.sysname);
  98. 	maybe_print_name(CMD_UNAME_NODENAME, name.nodename);
  99. 	maybe_print_name(CMD_UNAME_RELEASE, name.release);
  100. 	maybe_print_name(CMD_UNAME_VERSION, name.version);
  101. 	maybe_print_name(CMD_UNAME_MACHINE, name.machine);
  103. 	printf("\n");
  105. 	return 0;
  106. }