On a FreeBSD system, you can use the who command to display a list of users who are currently logged in to the system.
To use the who command, simply enter who on the command line:
$ who
This will display a list of users who are currently logged in, along with their login names, terminal names, and login times.
For example, the output of the who command might look like this:
user1 ttyv0 Mon Dec 20 12:34 user2 ttyv1 Mon Dec 20 12:35
The who command displays only the users who are logged in to the local system. If you want to see a list of users who are logged in to other systems on the network, you can use the rwho command.
For more information about the who command, you can refer to the who man page by running man who on the command line.