1/* The `struct utmp' type, describing entries in the utmp file.
2 Copyright (C) 1993-2026 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#ifndef _UTMP_H
20# error "Never include <bits/utmp.h> directly; use <utmp.h> instead."
21#endif
22
23#include <paths.h>
24#include <sys/time.h>
25#include <sys/types.h>
26#include <bits/wordsize.h>
27
28
29#define UT_LINESIZE 32
30#define UT_NAMESIZE 32
31#define UT_HOSTSIZE 256
32
33
34/* The structure describing an entry in the database of
35 previous logins. */
36struct lastlog
37 {
38#if __WORDSIZE_TIME64_COMPAT32
39 __uint32_t ll_time;
40#else
41 __time_t ll_time;
42#endif
43 char ll_line[UT_LINESIZE];
44 char ll_host[UT_HOSTSIZE];
45 };
46
47
48/* The structure describing the status of a terminated process. This
49 type is used in `struct utmp' below. */
50struct exit_status
51 {
52 short int e_termination; /* Process termination status. */
53 short int e_exit; /* Process exit status. */
54 };
55
56
57/* The structure describing an entry in the user accounting database. */
58struct utmp
59{
60 short int ut_type; /* Type of login. */
61 pid_t ut_pid; /* Process ID of login process. */
62 char ut_line[UT_LINESIZE]
63 __attribute_nonstring__; /* Devicename. */
64 char ut_id[4]
65 __attribute_nonstring__; /* Inittab ID. */
66 char ut_user[UT_NAMESIZE]
67 __attribute_nonstring__; /* Username. */
68 char ut_host[UT_HOSTSIZE]
69 __attribute_nonstring__; /* Hostname for remote login. */
70 struct exit_status ut_exit; /* Exit status of a process marked
71 as DEAD_PROCESS. */
72/* The ut_session and ut_tv fields must be the same size when compiled
73 32- and 64-bit. This allows data files and shared memory to be
74 shared between 32- and 64-bit applications. */
75#if __WORDSIZE_TIME64_COMPAT32
76 int32_t ut_session; /* Session ID, used for windowing. */
77 struct
78 {
79 __uint32_t tv_sec; /* Seconds. */
80 int32_t tv_usec; /* Microseconds. */
81 } ut_tv; /* Time entry was made. */
82#else
83 long int ut_session; /* Session ID, used for windowing. */
84 struct timeval ut_tv; /* Time entry was made. */
85#endif
86
87 int32_t ut_addr_v6[4]; /* Internet address of remote host. */
88 char __glibc_reserved[20]; /* Reserved for future use. */
89};
90
91/* Backwards compatibility hacks. */
92#define ut_name ut_user
93#ifndef _NO_UT_TIME
94/* We have a problem here: `ut_time' is also used otherwise. Define
95 _NO_UT_TIME if the compiler complains. */
96# define ut_time ut_tv.tv_sec
97#endif
98#define ut_xtime ut_tv.tv_sec
99#define ut_addr ut_addr_v6[0]
100
101
102/* Values for the `ut_type' field of a `struct utmp'. */
103#define EMPTY 0 /* No valid user accounting information. */
104
105#define RUN_LVL 1 /* The system's runlevel. */
106#define BOOT_TIME 2 /* Time of system boot. */
107#define NEW_TIME 3 /* Time after system clock changed. */
108#define OLD_TIME 4 /* Time when system clock changed. */
109
110#define INIT_PROCESS 5 /* Process spawned by the init process. */
111#define LOGIN_PROCESS 6 /* Session leader of a logged in user. */
112#define USER_PROCESS 7 /* Normal process. */
113#define DEAD_PROCESS 8 /* Terminated process. */
114
115#define ACCOUNTING 9
116
117/* Old Linux name for the EMPTY type. */
118#define UT_UNKNOWN EMPTY
119
120
121/* Tell the user that we have a modern system with UT_HOST, UT_PID,
122 UT_TYPE, UT_ID and UT_TV fields. */
123#define _HAVE_UT_TYPE 1
124#define _HAVE_UT_PID 1
125#define _HAVE_UT_ID 1
126#define _HAVE_UT_TV 1
127#define _HAVE_UT_HOST 1