Command library / who
who
Show who is currently logged in
Reports every account with an active session on this host right now — who, from where, and since when. Where last looks backward through login history, who is the instant snapshot of right now.
Practice whoUsage
who [-a] [-b] [-q]
Options and flags
-a, --allshow extra detail: login time, idle time, process ID
-b, --boottime of the last system boot
-q, --countonly the login names, plus the number of users logged in
Examples
whoEvery account with an active session right now, and where they connected from.
who -aThe same list, with extra detail per session.
who -qJust the login names and a total count.
who -bWhen the system last booted.
Common mistakes
whom who
The command is simply 'who' — 'whom' isn't a real program and the shell would report it as not found.