]>
Commit | Line | Data |
---|---|---|
3d54a910 MK |
1 | .\" Copyright (c) 1993 Michael Haardt (michael@cantor.informatik.rwth-aachen.de), |
2 | .\" Fri Apr 2 11:32:09 MET DST 1993 | |
fea681da | 3 | .\" |
1dd72f9c | 4 | .\" %%%LICENSE_START(GPLv2+_DOC_FULL) |
fea681da MK |
5 | .\" This is free documentation; you can redistribute it and/or |
6 | .\" modify it under the terms of the GNU General Public License as | |
7 | .\" published by the Free Software Foundation; either version 2 of | |
8 | .\" the License, or (at your option) any later version. | |
9 | .\" | |
10 | .\" The GNU General Public License's references to "object code" | |
11 | .\" and "executables" are to be interpreted as the output of any | |
12 | .\" document formatting or typesetting system, including | |
13 | .\" intermediate and printed output. | |
14 | .\" | |
15 | .\" This manual is distributed in the hope that it will be useful, | |
16 | .\" but WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | .\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
18 | .\" GNU General Public License for more details. | |
19 | .\" | |
20 | .\" You should have received a copy of the GNU General Public | |
c715f741 MK |
21 | .\" License along with this manual; if not, see |
22 | .\" <http://www.gnu.org/licenses/>. | |
6a8d8745 | 23 | .\" %%%LICENSE_END |
c13182ef | 24 | .\" |
fea681da MK |
25 | .\" Modified 1993-07-25 by Rik Faith (faith@cs.unc.edu) |
26 | .\" Modified 1995-02-26 by Michael Haardt | |
27 | .\" Modified 1996-07-20 by Michael Haardt | |
e00c3a07 | 28 | .\" Modified 1997-07-02 by Nicolás Lichtmaier <nick@debian.org> |
fea681da | 29 | .\" Modified 2004-10-31 by aeb, following Gwenole Beauchesne |
4b8c67d9 | 30 | .TH UTMP 5 2017-09-15 "Linux" "Linux Programmer's Manual" |
fea681da MK |
31 | .SH NAME |
32 | utmp, wtmp \- login records | |
33 | .SH SYNOPSIS | |
62218dc0 | 34 | .B #include <utmp.h> |
fea681da MK |
35 | .SH DESCRIPTION |
36 | The | |
37 | .I utmp | |
38 | file allows one to discover information about who is currently using the | |
c13182ef MK |
39 | system. |
40 | There may be more users currently using the system, because not | |
fea681da MK |
41 | all programs use utmp logging. |
42 | .PP | |
43 | .B Warning: | |
44 | .I utmp | |
01f59bf3 PC |
45 | must not be writable by the user class "other", |
46 | because many system programs (foolishly) | |
c13182ef MK |
47 | depend on its integrity. |
48 | You risk faked system logfiles and | |
fea681da MK |
49 | modifications of system files if you leave |
50 | .I utmp | |
01f59bf3 | 51 | writable to any user other than the owner and group owner of the file. |
fea681da | 52 | .PP |
c5571b61 | 53 | The file is a sequence of |
897ea723 MK |
54 | .I utmp |
55 | structures, | |
56 | declared as follows in | |
57 | .IR <utmp.h> | |
58 | (note that this is only one of several definitions | |
fea681da | 59 | around; details depend on the version of libc): |
78bffc45 | 60 | .PP |
088a639b | 61 | .in +4n |
bdd915e2 | 62 | .EX |
f6f269ab MK |
63 | /* Values for ut_type field, below */ |
64 | ||
377dda59 MK |
65 | #define EMPTY 0 /* Record does not contain valid info |
66 | (formerly known as UT_UNKNOWN on Linux) */ | |
67 | #define RUN_LVL 1 /* Change in system run-level (see | |