]>
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 | .\" |
e4a74ca8 | 4 | .\" SPDX-License-Identifier: GPL-2.0-or-later |
c13182ef | 5 | .\" |
fea681da MK |
6 | .\" Modified 1993-07-25 by Rik Faith (faith@cs.unc.edu) |
7 | .\" Modified 1995-02-26 by Michael Haardt | |
8 | .\" Modified 1996-07-20 by Michael Haardt | |
e00c3a07 | 9 | .\" Modified 1997-07-02 by Nicolás Lichtmaier <nick@debian.org> |
fea681da | 10 | .\" Modified 2004-10-31 by aeb, following Gwenole Beauchesne |
1d767b55 | 11 | .TH UTMP 5 2021-03-22 "Linux" "Linux Programmer's Manual" |
fea681da MK |
12 | .SH NAME |
13 | utmp, wtmp \- login records | |
14 | .SH SYNOPSIS | |
c7db92b9 | 15 | .nf |
62218dc0 | 16 | .B #include <utmp.h> |
c7db92b9 | 17 | .fi |
fea681da MK |
18 | .SH DESCRIPTION |
19 | The | |
20 | .I utmp | |
21 | file allows one to discover information about who is currently using the | |
c13182ef MK |
22 | system. |
23 | There may be more users currently using the system, because not | |
fea681da MK |
24 | all programs use utmp logging. |
25 | .PP | |
26 | .B Warning: | |
27 | .I utmp | |
01f59bf3 PC |
28 | must not be writable by the user class "other", |
29 | because many system programs (foolishly) | |
c13182ef MK |
30 | depend on its integrity. |
31 | You risk faked system logfiles and | |
fea681da MK |
32 | modifications of system files if you leave |
33 | .I utmp | |
01f59bf3 | 34 | writable to any user other than the owner and group owner of the file. |
fea681da | 35 | .PP |
c5571b61 | 36 | The file is a sequence of |
897ea723 MK |
37 | .I utmp |
38 | structures, | |
39 | declared as follows in | |
1ae6b2c7 | 40 | .I <utmp.h> |
897ea723 | 41 | (note that this is only one of several definitions |
fea681da | 42 | around; details depend on the version of libc): |
78bffc45 | 43 | .PP |
088a639b | 44 | .in +4n |
bdd915e2 | 45 | .EX |
f6f269ab MK |
46 | /* Values for ut_type field, below */ |
47 | ||
377dda59 MK |
48 | #define EMPTY 0 /* Record does not contain valid info |
49 | (formerly known as UT_UNKNOWN on Linux) */ | |
d064d41a | 50 | #define RUN_LVL 1 /* Change in system run\-level (see |
4a95bc02 | 51 | \fBinit\fP(1)) */ |