/var/run/utmp
list of users on the system
Display users who are logged on and what they are doing
w [-ahi]
[-M
core]
[-N
system]
[user]
The w utility prints a summary of the current activity on the system, including what each user is doing. The first line displays the current time of day, how long the system has been running, the number of users logged into the system, and the load averages. The load average numbers give the number of jobs in the run queue averaged over 1, 5 and 15 minutes.
The fields output are the user's login name, the name of the terminal the user is on, the host from which the user is logged in, the time the user logged on, the time since the user last typed anything, and the name and arguments of the current process.
The options are as follows:
-a
Attempt to translate network addresses into names.
-h
Suppress the heading.
-i
Output is sorted by idle time.
-M core
Extract values associated with the name list from the specified core instead of the running kernel.
-N system
Extract the name list from the specified system instead of the running kernel.
If a user name is specified, the output is restricted to that user.
/var/run/utmp
list of users on the system
61 releases since OpenBSD 2.1; the text changed 15 times.