| /* vi: set sw=4 ts=4: */ |
| /* |
| * last implementation for busybox |
| * |
| * Copyright (C) 2003-2004 by Erik Andersen <andersen@codepoet.org> |
| * |
| * Licensed under the GPL version 2, see the file LICENSE in this tarball. |
| */ |
| |
| #include "libbb.h" |
| #include <utmp.h> |
| |
| /* NB: ut_name and ut_user are the same field, use only one name (ut_user) |
| * to reduce confusion */ |
| |
| #ifndef SHUTDOWN_TIME |
| # define SHUTDOWN_TIME 254 |
| #endif |
| |
| /* Grr... utmp char[] members do not have to be nul-terminated. |
| * Do what we can while still keeping this reasonably small. |
| * Note: We are assuming the ut_id[] size is fixed at 4. */ |
| |
| #if defined UT_LINESIZE \ |
| && ((UT_LINESIZE != 32) || (UT_NAMESIZE != 32) || (UT_HOSTSIZE != 256)) |
| #error struct utmp member char[] size(s) have changed! |
| #elif defined __UT_LINESIZE \ |
| && ((__UT_LINESIZE != 32) || (__UT_NAMESIZE != 64) || (__UT_HOSTSIZE != 256)) |
| #error struct utmp member char[] size(s) have changed! |
| #endif |
| |
| #if EMPTY != 0 || RUN_LVL != 1 || BOOT_TIME != 2 || NEW_TIME != 3 || \ |
| OLD_TIME != 4 |
| #error Values for the ut_type field of struct utmp changed |
| #endif |
| |
| int last_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| int last_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) |
| { |
| struct utmp ut; |
| int n, file = STDIN_FILENO; |
| time_t t_tmp; |
| off_t pos; |
| static const char _ut_usr[] ALIGN1 = |
| "runlevel\0" "reboot\0" "shutdown\0"; |
| static const char _ut_lin[] ALIGN1 = |
| "~\0" "{\0" "|\0" /* "LOGIN\0" "date\0" */; |
| enum { |
| TYPE_RUN_LVL = RUN_LVL, /* 1 */ |
| TYPE_BOOT_TIME = BOOT_TIME, /* 2 */ |
| TYPE_SHUTDOWN_TIME = SHUTDOWN_TIME |
| }; |
| enum { |
| _TILDE = EMPTY, /* 0 */ |
| TYPE_NEW_TIME, /* NEW_TIME, 3 */ |
| TYPE_OLD_TIME /* OLD_TIME, 4 */ |
| }; |
| |
| if (argv[1]) { |
| bb_show_usage(); |
| } |
| file = xopen(bb_path_wtmp_file, O_RDONLY); |
| |
| printf("%-10s %-14s %-18s %-12.12s %s\n", |
| "USER", "TTY", "HOST", "LOGIN", "TIME"); |
| /* yikes. We reverse over the file and that is a not too elegant way */ |
| pos = xlseek(file, 0, SEEK_END); |
| pos = lseek(file, pos - sizeof(ut), SEEK_SET); |
| while ((n = full_read(file, &ut, sizeof(ut))) > 0) { |
| if (n != sizeof(ut)) { |
| bb_perror_msg_and_die("short read"); |
| } |
| n = index_in_strings(_ut_lin, ut.ut_line); |
| if (n == _TILDE) { /* '~' */ |
| #if 1 |
| /* do we really need to be cautious here? */ |
| n = index_in_strings(_ut_usr, ut.ut_user); |
| if (++n > 0) |
| ut.ut_type = n != 3 ? n : SHUTDOWN_TIME; |
| #else |
| if (strncmp(ut.ut_user, "shutdown", 8) == 0) |
| ut.ut_type = SHUTDOWN_TIME; |
| else if (strncmp(ut.ut_user, "reboot", 6) == 0) |
| ut.ut_type = BOOT_TIME; |
| else if (strncmp(ut.ut_user, "runlevel", 8) == 0) |
| ut.ut_type = RUN_LVL; |
| #endif |
| } else { |
| if (ut.ut_user[0] == '\0' || strcmp(ut.ut_user, "LOGIN") == 0) { |
| /* Don't bother. This means we can't find how long |
| * someone was logged in for. Oh well. */ |
| goto next; |
| } |
| if (ut.ut_type != DEAD_PROCESS |
| && ut.ut_user[0] |
| && ut.ut_line[0] |
| ) { |
| ut.ut_type = USER_PROCESS; |
| } |
| if (strcmp(ut.ut_user, "date") == 0) { |
| if (n == TYPE_OLD_TIME) { /* '|' */ |
| ut.ut_type = OLD_TIME; |
| } |
| if (n == TYPE_NEW_TIME) { /* '{' */ |
| ut.ut_type = NEW_TIME; |
| } |
| } |
| } |
| |
| if (ut.ut_type != USER_PROCESS) { |
| switch (ut.ut_type) { |
| case OLD_TIME: |
| case NEW_TIME: |
| case RUN_LVL: |
| case SHUTDOWN_TIME: |
| goto next; |
| case BOOT_TIME: |
| strcpy(ut.ut_line, "system boot"); |
| } |
| } |
| /* manpages say ut_tv.tv_sec *is* time_t, |
| * but some systems have it wrong */ |
| t_tmp = (time_t)ut.ut_tv.tv_sec; |
| printf("%-10s %-14s %-18s %-12.12s\n", |
| ut.ut_user, ut.ut_line, ut.ut_host, ctime(&t_tmp) + 4); |
| next: |
| pos -= sizeof(ut); |
| if (pos <= 0) |
| break; /* done. */ |
| xlseek(file, pos, SEEK_SET); |
| } |
| |
| fflush_stdout_and_exit(EXIT_SUCCESS); |
| } |