who(1) General Commands Manual who(1)
Name
who - print who and where users are logged in
Syntax
who [who-file] [am i]
Description
The command, without an argument, lists the login name, terminal name, and login time for each current UNIX user.
Without an argument, examines the /etc/utmp file to obtain its information. If a file is given, that file is examined. Typically the
given file will be /usr/adm/wtmp, which contains a record of all the logins since it was created. Then lists logins, logouts, and crashes
since the creation of the wtmp file. Each login is listed with user name, terminal name (with /dev/ suppressed), and date and time. When
an argument is given, logouts produce a similar line without a user name. Reboots produce a line with `~' in the place of the device name,
and a fossil time indicative of when the system went down.
With two arguments, as in `who am I' (and also `who are you'), tells who you are logged in as.
Files
/etc/utmp
See Also
getuid(2), utmp(5)
who(1)
