last.c 2.4 KB

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071727374757677787980818283848586878889
  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 ATTRIBUTE_UNUSED)
  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 = full_read(file, &ut, sizeof(ut))) > 0) {
  36. if (n != sizeof(ut)) {
  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", 8) == 0)
  45. ut.ut_type = RUN_LVL;
  46. } else {
  47. if (ut.ut_name[0] == '\0' || strcmp(ut.ut_name, "LOGIN") == 0) {
  48. /* Don't bother. This means we can't find how long
  49. * someone was logged in for. Oh well. */
  50. continue;
  51. }
  52. if (ut.ut_type != DEAD_PROCESS
  53. && ut.ut_name[0] && ut.ut_line[0]
  54. ) {
  55. ut.ut_type = USER_PROCESS;
  56. }
  57. if (strcmp(ut.ut_name, "date") == 0) {
  58. if (ut.ut_line[0] == '|') ut.ut_type = OLD_TIME;
  59. if (ut.ut_line[0] == '{') ut.ut_type = NEW_TIME;
  60. }
  61. }
  62. if (ut.ut_type != USER_PROCESS) {
  63. switch (ut.ut_type) {
  64. case OLD_TIME:
  65. case NEW_TIME:
  66. case RUN_LVL:
  67. case SHUTDOWN_TIME:
  68. continue;
  69. case BOOT_TIME:
  70. strcpy(ut.ut_line, "system boot");
  71. break;
  72. }
  73. }
  74. t_tmp = (time_t)ut.ut_tv.tv_sec;
  75. printf("%-10s %-14s %-18s %-12.12s\n", ut.ut_user, ut.ut_line, ut.ut_host,
  76. ctime(&t_tmp) + 4);
  77. }
  78. fflush_stdout_and_exit(EXIT_SUCCESS);
  79. }