UTMPX(5) File Formats Manual UTMPX(5)
NAME
utmpx, wtmpx, lastlogxuser accounting database
SYNOPSIS
#include <utmpx.h>
DESCRIPTION
In contrast to utmp and wtmp, the extended databases in utmpx and wtmpx reserve more space for logging hostnames, and also information on a process' ID, termination signal and exit status.
 
The <utmpx.h> header defines the structures and functions for logging user. Currently logged in users are tracked in /var/run/utmpx, a list of all logins and logouts, as well as all shutdowns, reboots and date changes, is kept in /var/log/wtmpx, and the last login of each user is noted in /var/log/lastlogx.
 
The interface to the utmpx file is described in getutxent(3).
 
The wtmpx file can grow rapidly on busy systems, and is normally rotated with newsyslog(8).
 
In the event of a date change, a shutdown, or a reboot, the following items are logged in the wtmpx file:
date
The system time has been manually or automatically updated by date(1). The command name date is recorded in the field ut_name. In the field ut_line, the character ‘\*(Ba' indicates the time prior to the change, and the character ‘{' indicates the new time.
reboot
shutdown
A system reboot or shutdown has been initiated. The character ‘~' is placed in the field ut_line, and reboot or shutdown in the field ut_name (see shutdown(8) and reboot(8)), using logwtmpx(3).
 
FILES
/var/run/utmpx
The utmpx file.
/var/log/wtmpx
The wtmpx file.
/var/log/lastlogx
The lastlogx file.
SEE ALSO