last.c 2.4 KB

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  1. /* vi: set sw=4 ts=4: */
  2. /*
  3. * last implementation for busybox
  4. *
  5. * Copyright (C) 2003-2004 by Erik Andersen <andersen@codepoet.org>
  6. *
  7. * Licensed under the GPL version 2, see the file LICENSE in this tarball.
  8. */
  9. #include "libbb.h"
  10. #include <utmp.h>
  11. #ifndef SHUTDOWN_TIME
  12. # define SHUTDOWN_TIME 254
  13. #endif
  14. /* Grr... utmp char[] members do not have to be nul-terminated.
  15. * Do what we can while still keeping this reasonably small.
  16. * Note: We are assuming the ut_id[] size is fixed at 4. */
  17. #if defined UT_LINESIZE \
  18. && ((UT_LINESIZE != 32) || (UT_NAMESIZE != 32) || (UT_HOSTSIZE != 256))
  19. #error struct utmp member char[] size(s) have changed!
  20. #elif defined __UT_LINESIZE \
  21. && ((__UT_LINESIZE != 32) || (__UT_NAMESIZE != 64) || (__UT_HOSTSIZE != 256))
  22. #error struct utmp member char[] size(s) have changed!
  23. #endif
  24. int last_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  25. int last_main(int argc, char **argv)
  26. {
  27. struct utmp ut;
  28. int n, file = STDIN_FILENO;
  29. time_t t_tmp;
  30. if (argc > 1) {
  31. bb_show_usage();
  32. }
  33. file = xopen(bb_path_wtmp_file, O_RDONLY);
  34. printf("%-10s %-14s %-18s %-12.12s %s\n", "USER", "TTY", "HOST", "LOGIN", "TIME");
  35. while ((n = safe_read(file, (void*)&ut, sizeof(struct utmp))) != 0) {
  36. if (n != sizeof(struct utmp)) {
  37. bb_perror_msg_and_die("short read");
  38. }
  39. if (ut.ut_line[0] == '~') {
  40. if (strncmp(ut.ut_user, "shutdown", 8) == 0)
  41. ut.ut_type = SHUTDOWN_TIME;
  42. else if (strncmp(ut.ut_user, "reboot", 6) == 0)
  43. ut.ut_type = BOOT_TIME;
  44. else if (strncmp(ut.ut_user, "runlevel", 7) == 0)
  45. ut.ut_type = RUN_LVL;
  46. } else {
  47. if (!ut.ut_name[0] || strcmp(ut.ut_name, "LOGIN") == 0 ||
  48. ut.ut_name[0] == 0)
  49. {
  50. /* Don't bother. This means we can't find how long
  51. * someone was logged in for. Oh well. */
  52. continue;
  53. }
  54. if (ut.ut_type != DEAD_PROCESS &&
  55. ut.ut_name[0] && ut.ut_line[0])
  56. {
  57. ut.ut_type = USER_PROCESS;
  58. }
  59. if (strcmp(ut.ut_name, "date") == 0) {
  60. if (ut.ut_line[0] == '|') ut.ut_type = OLD_TIME;
  61. if (ut.ut_line[0] == '{') ut.ut_type = NEW_TIME;
  62. }
  63. }
  64. if (ut.ut_type!=USER_PROCESS) {
  65. switch (ut.ut_type) {
  66. case OLD_TIME:
  67. case NEW_TIME:
  68. case RUN_LVL:
  69. case SHUTDOWN_TIME:
  70. continue;
  71. case BOOT_TIME:
  72. strcpy(ut.ut_line, "system boot");
  73. break;
  74. }
  75. }
  76. t_tmp = (time_t)ut.ut_tv.tv_sec;
  77. printf("%-10s %-14s %-18s %-12.12s\n", ut.ut_user, ut.ut_line, ut.ut_host,
  78. ctime(&t_tmp) + 4);
  79. }
  80. fflush_stdout_and_exit(EXIT_SUCCESS);
  81. }