who — show WHO is logged onSummary : `who’ prints the info (login name, terminal line, login time, and remote hostname or X display) about each user currently logged on. `who’ uses /var/run/utmp file to know abt the current users. Examples :
$ who -- Show who are all logged on. $ who -H -- Show info with header. $ who -m -- only hostname and user associated with stdin. $ who -q -- Show currently logged username and count. $ who -r -- Show the current run level. $ who -s -- Short form. $ who -T -- Add user's message status as +, - or ? $ who -a -- Show all info. $ who am i -- Your detail. $ who mom likes -- !? :-) $ who /var/log/wtmp -- Who has previously logged on.
Read : man who