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~/.local/bin tools and git-hooks git clone https://hacktivis.me/git/utils.git

env.c (1953B)

    

  1. // Collection of Unix tools, comparable to coreutils
  2. // SPDX-FileCopyrightText: 2017-2022 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
  3. // SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only
  5. #define _POSIX_C_SOURCE 200809L
  6. #include <assert.h>  // assert
  7. #include <errno.h>   // errno
  8. #include <stdbool.h> // bool, true, false
  9. #include <stdio.h>   // puts, perror, fprintf
  10. #include <stdlib.h>  // putenv
  11. #include <string.h>  // strchr
  12. #include <unistd.h>  // getopt, opt*
  14. extern char **environ;
  15. char *envclear[1];
  17. int export()
  18. {
  19. 	int i = 0;
  21. 	for(; environ[i] != NULL; i++)
  22. 	{
  23. 		if(puts(environ[i]) < 0)
  24. 		{
  25. 			perror("env: puts");
  26. 			return 1;
  27. 		}
  28. 	}
  30. 	return 0;
  31. }
  33. void
  34. usage()
  35. {
  36. 	fprintf(stderr, "env [-i] [-u key] [key=value ...] [command [args]]\n");
  37. }
  39. int
  40. main(int argc, char *argv[])
  41. {
  42. 	int c;
  43. 	bool flag_i = false;
  45. 	/* flawfinder: ignore. Old implementations of getopt should fix themselves */
  46. 	while((c = getopt(argc, argv, ":iu:")) != -1)
  47. 	{
  48. 		switch(c)
  49. 		{
  50. 		case 'i':
  51. 			flag_i = true;
  52. 			break;
  53. 		case 'u':
  54. 			unsetenv(optarg);
  55. 			break;
  56. 		case ':':
  57. 			fprintf(stderr, "Error: Missing operand for option: '-%c'\n", optopt);
  58. 			usage();
  59. 			return 1;
  60. 		case '?':
  61. 			fprintf(stderr, "Error: Unrecognised option: '-%c'\n", optopt);
  62. 			usage();
  63. 			return 1;
  64. 		default:
  65. 			assert(false);
  66. 		}
  67. 	}
  69. 	argc -= optind;
  70. 	argv += optind;
  72. 	if(flag_i)
  73. 	{
  74. 		environ     = envclear;
  75. 		envclear[0] = NULL;
  76. 	}
  78. 	for(; argv[0]; argv++, argc--)
  79. 	{
  80. 		char *sep = strchr(argv[0], '=');
  81. 		if(sep == NULL)
  82. 		{
  83. 			break;
  84. 		}
  86. 		*sep = 0;
  87. 		sep++;
  89. 		if(setenv(argv[0], sep, 1))
  90. 		{
  91. 			perror("env: setenv:");
  92. 			return 1;
  93. 		}
  94. 	}
  96. 	if(argc < 1)
  97. 	{
  98. 		return export();
  99. 	}
  101. 	assert(argv[0]);
  102. 	errno = 0;
  103. 	/* flawfinder: ignore. No restrictions on commands is intended */
  104. 	if(execvp(argv[0], argv) < 0)
  105. 	{
  106. 		if(errno == ENOENT)
  107. 		{
  108. 			perror("env: execve");
  109. 			return 127;
  110. 		}
  111. 		else
  112. 		{
  113. 			perror("env: execve");
  114. 			return 126;
  115. 		}
  116. 	}
  118. 	assert(false);
  119. }