| UTMPX(5) | File Formats Manual | UTMPX(5) | 
utmpx, wtmpx,
  lastlogx —
#include <utmpx.h>
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|’ indicates the time
      prior to the change, and the character
      ‘{’ indicates the new time.rebootshutdown~’ 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).utmpx file.wtmpx file.lastlogx file.| January 31, 2007 | NetBSD 10.1 |