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
10#include "libbb.h"
11#include <utmp.h>
12
13#ifndef SHUTDOWN_TIME
14#  define SHUTDOWN_TIME 254
15#endif
16
17/* Grr... utmp char[] members  do not have to be nul-terminated.
18 * Do what we can while still keeping this reasonably small.
19 * Note: We are assuming the ut_id[] size is fixed at 4. */
20
21#if defined UT_LINESIZE && ((UT_LINESIZE != 32) || (UT_NAMESIZE != 32) || (UT_HOSTSIZE \
22	!= 256))
23#error struct utmp member char[] size(s) have changed!
24#elif defined __UT_LINESIZE \
25	&& ((__UT_LINESIZE != 32) || (__UT_NAMESIZE != 64) || (__UT_HOSTSIZE != 256))
26#error struct utmp member char[] size(s) have changed!
27#endif
28
29int last_main(int argc, char **argv);
30int last_main(int argc, char **argv)
31{
32	struct utmp ut;
33	int n, file = STDIN_FILENO;
34	time_t t_tmp;
35
36	if (argc > 1) {
37		bb_show_usage();
38	}
39	file = xopen(bb_path_wtmp_file, O_RDONLY);
40
41	printf("%-10s %-14s %-18s %-12.12s %s\n", "USER", "TTY", "HOST", "LOGIN", "TIME");
42	while ((n = safe_read(file, (void*)&ut, sizeof(struct utmp))) != 0) {
43
44		if (n != sizeof(struct utmp)) {
45			bb_perror_msg_and_die("short read");
46		}
47
48		if (ut.ut_line[0] == '~') {
49			if (strncmp(ut.ut_user, "shutdown", 8) == 0)
50				ut.ut_type = SHUTDOWN_TIME;
51			else if (strncmp(ut.ut_user, "reboot", 6) == 0)
52				ut.ut_type = BOOT_TIME;
53			else if (strncmp(ut.ut_user, "runlevel", 7) == 0)
54				ut.ut_type = RUN_LVL;
55		} else {
56			if (!ut.ut_name[0] || strcmp(ut.ut_name, "LOGIN") == 0 ||
57					ut.ut_name[0] == 0)
58			{
59				/* Don't bother.  This means we can't find how long
60				 * someone was logged in for.  Oh well. */
61				continue;
62			}
63			if (ut.ut_type != DEAD_PROCESS &&
64					ut.ut_name[0] && ut.ut_line[0])
65			{
66				ut.ut_type = USER_PROCESS;
67			}
68			if (strcmp(ut.ut_name, "date") == 0) {
69				if (ut.ut_line[0] == '|') ut.ut_type = OLD_TIME;
70				if (ut.ut_line[0] == '{') ut.ut_type = NEW_TIME;
71			}
72		}
73
74		if (ut.ut_type!=USER_PROCESS) {
75			switch (ut.ut_type) {
76				case OLD_TIME:
77				case NEW_TIME:
78				case RUN_LVL:
79				case SHUTDOWN_TIME:
80					continue;
81				case BOOT_TIME:
82					strcpy(ut.ut_line, "system boot");
83					break;
84			}
85		}
86		t_tmp = (time_t)ut.ut_tv.tv_sec;
87		printf("%-10s %-14s %-18s %-12.12s\n", ut.ut_user, ut.ut_line, ut.ut_host,
88				ctime(&t_tmp) + 4);
89	}
90
91	fflush_stdout_and_exit(EXIT_SUCCESS);
92}
93