blob: 27f5a35ce08888f7c369e2b1925191161975cdf1 [file] [log] [blame]
Eric Andersen2e9c2572003-08-08 22:26:06 +00001/* vi: set sw=4 ts=4: */
2/*
3 * last implementation for busybox
4 *
Eric Andersenc7bda1c2004-03-15 08:29:22 +00005 * Copyright (C) 2003-2004 by Erik Andersen <andersen@codepoet.org>
Eric Andersen2e9c2572003-08-08 22:26:06 +00006 *
Denys Vlasenko0ef64bd2010-08-16 20:14:46 +02007 * Licensed under GPLv2, see file LICENSE in this source tree.
Eric Andersen2e9c2572003-08-08 22:26:06 +00008 */
9
Pere Orga5bc8c002011-04-11 03:29:49 +020010//usage:#define last_trivial_usage
11//usage: ""IF_FEATURE_LAST_FANCY("[-HW] [-f FILE]")
12//usage:#define last_full_usage "\n\n"
13//usage: "Show listing of the last users that logged into the system"
14//usage: IF_FEATURE_LAST_FANCY( "\n"
15//usage: "\nOptions:"
16/* //usage: "\n -H Show header line" */
17//usage: "\n -W Display with no host column truncation"
18//usage: "\n -f FILE Read from FILE instead of /var/log/wtmp"
19//usage: )
20
Denis Vlasenkob6adbf12007-05-26 19:00:18 +000021#include "libbb.h"
Eric Andersen2e9c2572003-08-08 22:26:06 +000022
Denis Vlasenkocd2663f2008-06-01 22:36:39 +000023/* NB: ut_name and ut_user are the same field, use only one name (ut_user)
24 * to reduce confusion */
25
Eric Andersen2e9c2572003-08-08 22:26:06 +000026#ifndef SHUTDOWN_TIME
27# define SHUTDOWN_TIME 254
28#endif
29
Denis Vlasenkob44c7902008-03-17 09:29:43 +000030/* Grr... utmp char[] members do not have to be nul-terminated.
Eric Andersen2e9c2572003-08-08 22:26:06 +000031 * Do what we can while still keeping this reasonably small.
32 * Note: We are assuming the ut_id[] size is fixed at 4. */
33
Bernhard Reutner-Fischer781e42d2006-05-26 14:41:40 +000034#if defined UT_LINESIZE \
35 && ((UT_LINESIZE != 32) || (UT_NAMESIZE != 32) || (UT_HOSTSIZE != 256))
36#error struct utmp member char[] size(s) have changed!
37#elif defined __UT_LINESIZE \
38 && ((__UT_LINESIZE != 32) || (__UT_NAMESIZE != 64) || (__UT_HOSTSIZE != 256))
Eric Andersen2e9c2572003-08-08 22:26:06 +000039#error struct utmp member char[] size(s) have changed!
40#endif
41
Denis Vlasenkodfd82822008-05-22 17:35:22 +000042#if EMPTY != 0 || RUN_LVL != 1 || BOOT_TIME != 2 || NEW_TIME != 3 || \
43 OLD_TIME != 4
44#error Values for the ut_type field of struct utmp changed
45#endif
46
Denis Vlasenko9b49a5e2007-10-11 10:05:36 +000047int last_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
Denys Vlasenko2ec91ae2010-01-04 14:15:38 +010048int last_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
Eric Andersen2e9c2572003-08-08 22:26:06 +000049{
50 struct utmp ut;
51 int n, file = STDIN_FILENO;
"Vladimir N. Oleynik"dd14ca02006-01-31 09:35:45 +000052 time_t t_tmp;
Denis Vlasenkodfd82822008-05-22 17:35:22 +000053 off_t pos;
54 static const char _ut_usr[] ALIGN1 =
55 "runlevel\0" "reboot\0" "shutdown\0";
56 static const char _ut_lin[] ALIGN1 =
57 "~\0" "{\0" "|\0" /* "LOGIN\0" "date\0" */;
58 enum {
Denys Vlasenkoe4dcba12010-10-28 18:57:19 +020059 TYPE_RUN_LVL = RUN_LVL, /* 1 */
60 TYPE_BOOT_TIME = BOOT_TIME, /* 2 */
Denis Vlasenkodfd82822008-05-22 17:35:22 +000061 TYPE_SHUTDOWN_TIME = SHUTDOWN_TIME
62 };
63 enum {
Denys Vlasenkoe4dcba12010-10-28 18:57:19 +020064 _TILDE = EMPTY, /* 0 */
65 TYPE_NEW_TIME, /* NEW_TIME, 3 */
66 TYPE_OLD_TIME /* OLD_TIME, 4 */
Denis Vlasenkodfd82822008-05-22 17:35:22 +000067 };
Eric Andersen2e9c2572003-08-08 22:26:06 +000068
Denys Vlasenko2ec91ae2010-01-04 14:15:38 +010069 if (argv[1]) {
Eric Andersen2e9c2572003-08-08 22:26:06 +000070 bb_show_usage();
71 }
Rob Landleyd921b2e2006-08-03 15:41:12 +000072 file = xopen(bb_path_wtmp_file, O_RDONLY);
Eric Andersen2e9c2572003-08-08 22:26:06 +000073
Denis Vlasenkod04e1fc2008-05-17 23:50:14 +000074 printf("%-10s %-14s %-18s %-12.12s %s\n",
75 "USER", "TTY", "HOST", "LOGIN", "TIME");
Denis Vlasenkodfd82822008-05-22 17:35:22 +000076 /* yikes. We reverse over the file and that is a not too elegant way */
77 pos = xlseek(file, 0, SEEK_END);
78 pos = lseek(file, pos - sizeof(ut), SEEK_SET);
Denis Vlasenkod0a071a2008-03-17 09:33:45 +000079 while ((n = full_read(file, &ut, sizeof(ut))) > 0) {
80 if (n != sizeof(ut)) {
Eric Andersen2e9c2572003-08-08 22:26:06 +000081 bb_perror_msg_and_die("short read");
82 }
Denis Vlasenkodfd82822008-05-22 17:35:22 +000083 n = index_in_strings(_ut_lin, ut.ut_line);
84 if (n == _TILDE) { /* '~' */
85#if 1
86/* do we really need to be cautious here? */
87 n = index_in_strings(_ut_usr, ut.ut_user);
88 if (++n > 0)
Bernhard Reutner-Fischer61082ec2008-05-22 22:05:55 +000089 ut.ut_type = n != 3 ? n : SHUTDOWN_TIME;
Denis Vlasenkodfd82822008-05-22 17:35:22 +000090#else
Eric Andersen2e9c2572003-08-08 22:26:06 +000091 if (strncmp(ut.ut_user, "shutdown", 8) == 0)
92 ut.ut_type = SHUTDOWN_TIME;
93 else if (strncmp(ut.ut_user, "reboot", 6) == 0)
94 ut.ut_type = BOOT_TIME;
Bernhard Reutner-Fischerc8f7a972008-05-05 14:45:32 +000095 else if (strncmp(ut.ut_user, "runlevel", 8) == 0)
Eric Andersen2e9c2572003-08-08 22:26:06 +000096 ut.ut_type = RUN_LVL;
Denis Vlasenkodfd82822008-05-22 17:35:22 +000097#endif
Eric Andersen2e9c2572003-08-08 22:26:06 +000098 } else {
Bernhard Reutner-Fischer62d85032008-06-01 10:10:22 +000099 if (ut.ut_user[0] == '\0' || strcmp(ut.ut_user, "LOGIN") == 0) {
Eric Andersenc7bda1c2004-03-15 08:29:22 +0000100 /* Don't bother. This means we can't find how long
Eric Andersen2e9c2572003-08-08 22:26:06 +0000101 * someone was logged in for. Oh well. */
Denis Vlasenkodfd82822008-05-22 17:35:22 +0000102 goto next;
Eric Andersen2e9c2572003-08-08 22:26:06 +0000103 }
Denis Vlasenkod0a071a2008-03-17 09:33:45 +0000104 if (ut.ut_type != DEAD_PROCESS
Denys Vlasenko3a416112010-04-05 22:10:38 +0200105 && ut.ut_user[0]
106 && ut.ut_line[0]
Denis Vlasenkod0a071a2008-03-17 09:33:45 +0000107 ) {
Eric Andersen2e9c2572003-08-08 22:26:06 +0000108 ut.ut_type = USER_PROCESS;
109 }
Bernhard Reutner-Fischer62d85032008-06-01 10:10:22 +0000110 if (strcmp(ut.ut_user, "date") == 0) {
Denis Vlasenkodfd82822008-05-22 17:35:22 +0000111 if (n == TYPE_OLD_TIME) { /* '|' */
Denis Vlasenkod04e1fc2008-05-17 23:50:14 +0000112 ut.ut_type = OLD_TIME;
113 }
Denis Vlasenkodfd82822008-05-22 17:35:22 +0000114 if (n == TYPE_NEW_TIME) { /* '{' */
Denis Vlasenkod04e1fc2008-05-17 23:50:14 +0000115 ut.ut_type = NEW_TIME;
116 }
Eric Andersen2e9c2572003-08-08 22:26:06 +0000117 }
118 }
119
Denis Vlasenkod0a071a2008-03-17 09:33:45 +0000120 if (ut.ut_type != USER_PROCESS) {
Eric Andersen2e9c2572003-08-08 22:26:06 +0000121 switch (ut.ut_type) {
122 case OLD_TIME:
123 case NEW_TIME:
124 case RUN_LVL:
125 case SHUTDOWN_TIME:
Denis Vlasenkodfd82822008-05-22 17:35:22 +0000126 goto next;
Eric Andersen2e9c2572003-08-08 22:26:06 +0000127 case BOOT_TIME:
128 strcpy(ut.ut_line, "system boot");
Eric Andersen2e9c2572003-08-08 22:26:06 +0000129 }
130 }
Denis Vlasenko0e525412008-07-11 13:57:08 +0000131 /* manpages say ut_tv.tv_sec *is* time_t,
132 * but some systems have it wrong */
"Vladimir N. Oleynik"dd14ca02006-01-31 09:35:45 +0000133 t_tmp = (time_t)ut.ut_tv.tv_sec;
Denis Vlasenkod04e1fc2008-05-17 23:50:14 +0000134 printf("%-10s %-14s %-18s %-12.12s\n",
135 ut.ut_user, ut.ut_line, ut.ut_host, ctime(&t_tmp) + 4);
Denis Vlasenkodfd82822008-05-22 17:35:22 +0000136 next:
Denis Vlasenko30f892a2008-05-25 01:14:14 +0000137 pos -= sizeof(ut);
138 if (pos <= 0)
Denis Vlasenkodfd82822008-05-22 17:35:22 +0000139 break; /* done. */
Denis Vlasenko30f892a2008-05-25 01:14:14 +0000140 xlseek(file, pos, SEEK_SET);
Eric Andersen2e9c2572003-08-08 22:26:06 +0000141 }
142
Denis Vlasenkof0ed3762006-10-26 23:21:47 +0000143 fflush_stdout_and_exit(EXIT_SUCCESS);
Eric Andersen2e9c2572003-08-08 22:26:06 +0000144}