Software & Apps Linux Learn the Linux Command - who Use 'who' to identify logged-in users Share Pin Email Print Linux Switching from Windows By Juergen Haas Writer Former Lifewire writer Juergen Haas is a software developer, data scientist, and a fan of the Linux operating system. our editorial process Juergen Haas Updated January 30, 2020 The Linux command who returns a list of all logged-in users. Synopsis The command takes the following format: who [OPTION]... [ FILE | ARG1 ARG2 ] Options The who command takes the following command switches: -a, --all: Same as -b -d --login -p -r -t -T -u-b, --boot: Time of last system boot-d, --dead: Print dead processes-H, --heading: Print line of column headings-i, --idle: Add idle time as HOURS:MINUTES, . or old (deprecated, use -u)--login: Print system login processes (equivalent to SUS -l)-l, --lookup: Attempt to canonicalize hostnames via DNS (-l is deprecated, use --lookup)-m: Only hostname and user associated with stdin-p, --process: Print active processes spawned by init-q, --count: All login names and number of users logged on-r, --runlevel: Print current runlevel-s, --short: Print only name, line, and time (default)-t, --time: Print last system clock change-T, -w, --mesg: Add user's message status as +, - or ?-u, --users: List users logged in--message: Same as -T--writable: Same as -T--help: Display this help and exit--version: Output version information and exit If FILE is not specified, the command assumes /var/run/utmp. Use the man command (% man) to see how a command is used on your particular computer.