YouTipLinux Comm Who
# Linux who Command
[ Linux Command Manual](#)
The Linux `who` command is used to display which users are currently logged into the system. The displayed information includes the user ID, the terminal being used, where they logged in from, login time, idle time, CPU usage, and actions, etc.
Permission required: All users can use it.
### Syntax
who -
**Parameter Description**:
* -H or --heading: Display header information for each column;
* -i or -u or --idle: Display idle time. If the user has performed any action within the last minute, it will be marked with a ".". If the user has been inactive for more than 24 hours, it will display the string "old";
* -m: This parameter has the same effect as specifying the string "am i";
* -q or --count: Only display the account names of users logged into the system and the total number of users;
* -s: This parameter is ignored and is only used to resolve compatibility issues with other versions of the `who` command;
* -w or -T or --mesg or --message or --writable: Display the user's message status column;
* --help: Online help;
* --version: Display version information.
### Examples
Display users currently logged into the system
# who //Display users currently logged into the system root tty7 2014-05-13 12:12 (:0) root pts/0 2014-05-14 17:09 (:0.0) root pts/1 2014-05-14 18:51 (192.168.1.17) root pts/2 2014-05-14 19:48 (192.168.1.17)
Display the header row
# who -H NAME LINE TIME COMMENT root tty7 2014-05-13 12:12 (:0) root pts/0 2014-05-14 17:09 (:0.0) root pts/1 2014-05-14 18:51 (192.168.1.17) root pts/2 2014-05-14 19:48 (192.168.1.17)
Display user login sources
# who -l -H NAME LINE TIME IDLE PID COMMENT LOGIN tty4 2014-05-13 12:11 852 id=4 LOGIN tty5 2014-05-13 12:11 855 id=5 LOGIN tty2 2014-05-13 12:11 862 id=2 LOGIN tty3 2014-05-13 12:11 864 id=3 LOGIN tty6 2014-05-13 12:11 867 id=6 LOGIN tty1 2014-05-13 12:11 1021 id=1
Display terminal attributes
# who -T -H NAME LINE TIME COMMENT root + tty7 2014-05-13 12:12 (:0) root + pts/0 2014-05-14 17:09 (:0.0) root - pts/1 2014-05-14 18:51 (192.168.1.17) root - pts/2 2014-05-14 19:48 (192.168.1.17)
Display only the current user
# who -m -H NAME LINE TIME COMMENT root pts/1 2014-05-14 18:51 (192.168.1.17)
Display in compact mode
# who -q root root root root # users=4
[ Linux Command Manual](#)