1 /* vi: set sw=4 ts=4: */
3 * last implementation for busybox
5 * Copyright (C) 2003-2004 by Erik Andersen <andersen@codepoet.org>
7 * Licensed under GPLv2, see file LICENSE in this source tree.
10 //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"
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"
23 /* NB: ut_name and ut_user are the same field, use only one name (ut_user)
24 * to reduce confusion */
27 # define SHUTDOWN_TIME 254
30 /* Grr... utmp char[] members do not have to be nul-terminated.
31 * Do what we can while still keeping this reasonably small.
32 * Note: We are assuming the ut_id[] size is fixed at 4. */
34 #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))
39 #error struct utmp member char[] size(s) have changed!
42 #if EMPTY != 0 || RUN_LVL != 1 || BOOT_TIME != 2 || NEW_TIME != 3 || \
44 #error Values for the ut_type field of struct utmp changed
47 int last_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
48 int last_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
51 int n, file = STDIN_FILENO;
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" */;
59 TYPE_RUN_LVL = RUN_LVL, /* 1 */
60 TYPE_BOOT_TIME = BOOT_TIME, /* 2 */
61 TYPE_SHUTDOWN_TIME = SHUTDOWN_TIME
64 _TILDE = EMPTY, /* 0 */
65 TYPE_NEW_TIME, /* NEW_TIME, 3 */
66 TYPE_OLD_TIME /* OLD_TIME, 4 */
72 file = xopen(bb_path_wtmp_file, O_RDONLY);
74 printf("%-10s %-14s %-18s %-12.12s %s\n",
75 "USER", "TTY", "HOST", "LOGIN", "TIME");
76 /* 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);
79 while ((n = full_read(file, &ut, sizeof(ut))) > 0) {
80 if (n != sizeof(ut)) {
81 bb_perror_msg_and_die("short read");
83 n = index_in_strings(_ut_lin, ut.ut_line);
84 if (n == _TILDE) { /* '~' */
86 /* do we really need to be cautious here? */
87 n = index_in_strings(_ut_usr, ut.ut_user);
89 ut.ut_type = n != 3 ? n : SHUTDOWN_TIME;
91 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;
95 else if (strncmp(ut.ut_user, "runlevel", 8) == 0)
99 if (ut.ut_user[0] == '\0' || strcmp(ut.ut_user, "LOGIN") == 0) {
100 /* Don't bother. This means we can't find how long
101 * someone was logged in for. Oh well. */
104 if (ut.ut_type != DEAD_PROCESS
108 ut.ut_type = USER_PROCESS;
110 if (strcmp(ut.ut_user, "date") == 0) {
111 if (n == TYPE_OLD_TIME) { /* '|' */
112 ut.ut_type = OLD_TIME;
114 if (n == TYPE_NEW_TIME) { /* '{' */
115 ut.ut_type = NEW_TIME;
120 if (ut.ut_type != USER_PROCESS) {
121 switch (ut.ut_type) {
128 strcpy(ut.ut_line, "system boot");
131 /* manpages say ut_tv.tv_sec *is* time_t,
132 * but some systems have it wrong */
133 t_tmp = (time_t)ut.ut_tv.tv_sec;
134 printf("%-10s %-14s %-18s %-12.12s\n",
135 ut.ut_user, ut.ut_line, ut.ut_host, ctime(&t_tmp) + 4);
140 xlseek(file, pos, SEEK_SET);
143 fflush_stdout_and_exit(EXIT_SUCCESS);