who

Display who is logged in and related data (processes, boot time). See also: whoami. More information: https://www.gnu.org/software/coreutils/manual/html_node/who-invocation.html.

Display the username, line, and time of all currently logged-in sessions:

who

Display all available information:

who {{[-a|--all]}}

Display all available information with table headers:

who {{[-aH|--all --heading]}}