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42#include "libbb.h"
43
44
45
46
47#ifndef SHUTDOWN_TIME
48# define SHUTDOWN_TIME 254
49#endif
50
51
52
53
54
55#if defined UT_LINESIZE \
56 && ((UT_LINESIZE != 32) || (UT_NAMESIZE != 32) || (UT_HOSTSIZE != 256))
57#error struct utmpx member char[] size(s) have changed!
58#elif defined __UT_LINESIZE \
59 && ((__UT_LINESIZE != 32) || (__UT_NAMESIZE != 32) || (__UT_HOSTSIZE != 256))
60
61#error struct utmpx member char[] size(s) have changed!
62#endif
63
64#if EMPTY != 0 || RUN_LVL != 1 || BOOT_TIME != 2 || NEW_TIME != 3 || \
65 OLD_TIME != 4
66#error Values for the ut_type field of struct utmpx changed
67#endif
68
69int last_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
70int last_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
71{
72 struct utmpx ut;
73 int n, file = STDIN_FILENO;
74 time_t t_tmp;
75 off_t pos;
76 static const char _ut_usr[] ALIGN1 =
77 "runlevel\0" "reboot\0" "shutdown\0";
78 static const char _ut_lin[] ALIGN1 =
79 "~\0" "{\0" "|\0" ;
80 enum {
81 TYPE_RUN_LVL = RUN_LVL,
82 TYPE_BOOT_TIME = BOOT_TIME,
83 TYPE_SHUTDOWN_TIME = SHUTDOWN_TIME
84 };
85 enum {
86 _TILDE = EMPTY,
87 TYPE_NEW_TIME,
88 TYPE_OLD_TIME
89 };
90
91 if (argv[1]) {
92 bb_show_usage();
93 }
94 file = xopen(bb_path_wtmp_file, O_RDONLY);
95
96 printf("%-10s %-14s %-18s %-12.12s %s\n",
97 "USER", "TTY", "HOST", "LOGIN", "TIME");
98
99 pos = xlseek(file, 0, SEEK_END);
100 pos = lseek(file, pos - sizeof(ut), SEEK_SET);
101 while ((n = full_read(file, &ut, sizeof(ut))) > 0) {
102 if (n != sizeof(ut)) {
103 bb_perror_msg_and_die("short read");
104 }
105 n = index_in_strings(_ut_lin, ut.ut_line);
106 if (n == _TILDE) {
107#if 1
108
109 n = index_in_strings(_ut_usr, ut.ut_user);
110 if (++n > 0)
111 ut.ut_type = n != 3 ? n : SHUTDOWN_TIME;
112#else
113 if (is_prefixed_with(ut.ut_user, "shutdown"))
114 ut.ut_type = SHUTDOWN_TIME;
115 else if (is_prefixed_with(ut.ut_user, "reboot"))
116 ut.ut_type = BOOT_TIME;
117 else if (is_prefixed_with(ut.ut_user, "runlevel"))
118 ut.ut_type = RUN_LVL;
119#endif
120 } else {
121 if (ut.ut_user[0] == '\0' || strcmp(ut.ut_user, "LOGIN") == 0) {
122
123
124 goto next;
125 }
126 if (ut.ut_type != DEAD_PROCESS
127 && ut.ut_user[0]
128 && ut.ut_line[0]
129 ) {
130 ut.ut_type = USER_PROCESS;
131 }
132 if (strcmp(ut.ut_user, "date") == 0) {
133 if (n == TYPE_OLD_TIME) {
134 ut.ut_type = OLD_TIME;
135 }
136 if (n == TYPE_NEW_TIME) {
137 ut.ut_type = NEW_TIME;
138 }
139 }
140 }
141
142 if (ut.ut_type != USER_PROCESS) {
143 switch (ut.ut_type) {
144 case OLD_TIME:
145 case NEW_TIME:
146 case RUN_LVL:
147 case SHUTDOWN_TIME:
148 goto next;
149 case BOOT_TIME:
150 strcpy(ut.ut_line, "system boot");
151 }
152 }
153
154
155 t_tmp = (time_t)ut.ut_tv.tv_sec;
156 printf("%-10s %-14s %-18s %-12.12s\n",
157 ut.ut_user, ut.ut_line, ut.ut_host, ctime(&t_tmp) + 4);
158 next:
159 pos -= sizeof(ut);
160 if (pos <= 0)
161 break;
162 xlseek(file, pos, SEEK_SET);
163 }
164
165 fflush_stdout_and_exit(EXIT_SUCCESS);
166}
167