Linux who Command

Linux 命令大全Linux Command Library

The Linux who command is used to display which users are currently on the system. The displayed information includes the user ID, the terminal in use, where they logged in from, login time, idle time, CPU usage, actions, and so on.

Permissions: All users can use it.

Syntax

who - [husfV] [user]

Parameter Description：

  • -H or --heading: Display the header information column for each field;
  • -i or -u or --idle: Display idle time. If the user has performed any action within the previous minute, it will be marked with a dot ".". If the user has had no action for more than 24 hours, the string "old" is displayed;
  • -m: This parameter has the same effect as specifying the "am i" string;
  • -q or --count: Only display the account names and total number of users logged into the system;
  • -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  //显示当前登录系统的用户
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 title bar

# 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 origin

# 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 命令大全Linux Command Library

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