2.11BSD/man/cat5/utmp.0
UTMP(5) UNIX Programmer's Manual UTMP(5)
NAME
utmp, wtmp - login records
SYNOPSIS
#include <utmp.h>
DESCRIPTION
The _u_t_m_p file records information about who is currently
using the system. The file is a sequence of entries with
the following structure declared in the include file:
/*
* Copyright (c) 1988 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley. The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* @(#)utmp.h 5.6.1 (2.11BSD) 1996/11/27
*/
#define _PATH_UTMP "/var/run/utmp"
#define _PATH_WTMP "/usr/adm/wtmp"
#define UT_NAMESIZE 15
#define UT_LINESIZE 8
#define UT_HOSTSIZE 16
struct utmp {
char ut_line[UT_LINESIZE];
char ut_name[UT_NAMESIZE];
char ut_host[UT_HOSTSIZE];
long ut_time;
};
This structure gives the name of the special file associated
with the user's terminal, the user's login name, and the
time of the login in the form of _t_i_m_e(3C).
The _w_t_m_p file records all logins and logouts. A null user
name indicates a logout on the associated terminal. Furth-
ermore, the terminal name `~' indicates that the system was
rebooted at the indicated time; the adjacent pair of entries
with terminal names `|' and `{' indicate the system-
Printed 11/26/99 November 27, 1996 1
UTMP(5) UNIX Programmer's Manual UTMP(5)
maintained time just before and just after a _d_a_t_e command
has changed the system's idea of the time.
_W_t_m_p is maintained by _l_o_g_i_n(1) and _i_n_i_t(8). Neither of
these programs creates the file, so if it is removed
record-keeping is turned off. It is summarized by _a_c(8).
FILES
/var/run/utmp
/usr/adm/wtmp
SEE ALSO
login(1), init(8), who(1), ac(8)
Printed 11/26/99 November 27, 1996 2