mknod.c 2.3 KB

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  1. /* vi: set sw=4 ts=4: */
  2. /*
  3. * mknod implementation for busybox
  4. *
  5. * Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org>
  6. *
  7. * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  8. */
  9. //config:config MKNOD
  10. //config: bool "mknod (4.5 kb)"
  11. //config: default y
  12. //config: help
  13. //config: mknod is used to create FIFOs or block/character special
  14. //config: files with the specified names.
  15. //applet:IF_MKNOD(APPLET_NOEXEC(mknod, mknod, BB_DIR_BIN, BB_SUID_DROP, mknod))
  16. //kbuild:lib-$(CONFIG_MKNOD) += mknod.o
  17. /* BB_AUDIT SUSv3 N/A -- Matches GNU behavior. */
  18. //usage:#define mknod_trivial_usage
  19. //usage: "[-m MODE] " IF_SELINUX("[-Z] ") "NAME TYPE [MAJOR MINOR]"
  20. //usage:#define mknod_full_usage "\n\n"
  21. //usage: "Create a special file (block, character, or pipe)\n"
  22. //usage: "\n -m MODE Creation mode (default a=rw)"
  23. //usage: IF_SELINUX(
  24. //usage: "\n -Z Set security context"
  25. //usage: )
  26. //usage: "\nTYPE:"
  27. //usage: "\n b Block device"
  28. //usage: "\n c or u Character device"
  29. //usage: "\n p Named pipe (MAJOR MINOR must be omitted)"
  30. //usage:
  31. //usage:#define mknod_example_usage
  32. //usage: "$ mknod /dev/fd0 b 2 0\n"
  33. //usage: "$ mknod -m 644 /tmp/pipe p\n"
  34. #ifdef __linux__
  35. # include <sys/sysmacros.h> // For makedev
  36. #endif
  37. #include "libbb.h"
  38. #include "libcoreutils/coreutils.h"
  39. /* This is a NOEXEC applet. Be very careful! */
  40. static const char modes_chars[] ALIGN1 = { 'p', 'c', 'u', 'b', 0, 1, 1, 2 };
  41. static const mode_t modes_cubp[] = { S_IFIFO, S_IFCHR, S_IFBLK };
  42. int mknod_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  43. int mknod_main(int argc UNUSED_PARAM, char **argv)
  44. {
  45. mode_t mode;
  46. dev_t dev;
  47. const char *type, *arg;
  48. mode = getopt_mk_fifo_nod(argv);
  49. argv += optind;
  50. //argc -= optind;
  51. if (!argv[0] || !argv[1])
  52. bb_show_usage();
  53. type = strchr(modes_chars, argv[1][0]);
  54. if (!type)
  55. bb_show_usage();
  56. mode |= modes_cubp[(int)(type[4])];
  57. dev = 0;
  58. arg = argv[2];
  59. if (*type != 'p') {
  60. if (!argv[2] || !argv[3])
  61. bb_show_usage();
  62. /* Autodetect what the system supports; these macros should
  63. * optimize out to two constants. */
  64. dev = makedev(xatoul_range(argv[2], 0, major(UINT_MAX)),
  65. xatoul_range(argv[3], 0, minor(UINT_MAX)));
  66. arg = argv[4];
  67. }
  68. if (arg)
  69. bb_show_usage();
  70. if (mknod(argv[0], mode, dev) != 0) {
  71. bb_simple_perror_msg_and_die(argv[0]);
  72. }
  73. return EXIT_SUCCESS;
  74. }