/var/run/utmpx
connect time accounting file
Connect time accounting
ac [-dp]
[-t
tty]
[-w
wtmp]
[users ...]
By default, a record of individual login and logout times are recorded by login(1) and init(8), respectively to syslogd(8). The ac utility examines these records and writes the accumulated connect time (in hours) for all logins to the standard output.
The options are as follows:
-d
Display the connect times in 24 hour chunks.
-p
Print individual users' totals.
-t tty
Only do accounting logins on certain ttys. The tty specification can start with '!' to indicate not this tty and end with '*' to indicate all similarly named ttys. Multiple -t flags may be specified.
-w wtmp
Read connect time data from wtmp instead of the default, reading from the log(1).
Display totals for the given individuals only.
If no arguments are given, ac displays the total connect time for all accounts with login sessions recorded in log(1).
/var/run/utmpx
connect time accounting file
The ac utility exits 0 on success, and >0 if an error occurs.
Allow times recorded in modems to be charged out at a different rate than other:
ac -p -t "ttyd*" > modems ac -p -t "!ttyd*" > other
163 releases since Mac OS X 10.0; the text changed 3 times.
-t since macOS 13.0.