


How to check how many users are logged in in Linux
View method: 1. Use the w command. This command is used to display the user information currently logged in to the system. The syntax is "w [-fhlsuV][user name]"; 2. Use the who command. This command uses To display which users are on the system, the syntax is "who [parameter]".
#The operating environment of this tutorial: linux7.3 system, Dell G3 computer.
How to check how many users are logged in in Linux
1. Use the w command to check the process information being used by the logged-in user
Linux w command is used Displays the information of users currently logged into the system.
Execute this command to know who are the users currently logged into the system and the programs they are executing.
Executing the w command alone will display all users. You can also specify a user name to display only the relevant information of a certain user.
Syntax
w [-fhlsuV][用户名称]
Parameter description:
-f Turn on or off the display of where the user logs in to the system.
-h Does not display the title information column of each field.
-l Use detailed format list, this is the default value.
-s Use a concise format list and do not display the user login time, terminal stage operations and CPU time consumed by the program.
-u Ignore the name of the executing program and information about the CPU time consumed by the program.
-V Display version information. The
w command is used to display the names of users who have logged in to the system and what they are doing. The information used by this command comes from the /var/run/utmp file. The information output by the w command includes:
User name
The user’s machine name or tty number
Remote host address
The time the user logged into the system
Idle time (little effect)
-
The time taken by the process attached to the tty (terminal) (JCPU time)
The time taken by the current process (PCPU time)
The command currently being used by the user
is as follows:
# w // 显示当前用户登录信息及执行的命令 19:50:14 up 9:27, 4 users, load average: 0.31, 0.26, 0.18 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT root tty7 :0 Thu12 31:39m 10:10 0.60s gnome-session root pts/0 :0.0 17:09 2:18m 15.26s 0.15s bash root pts/1 192.168.1.17 18:51 1.00s 1.24s 0.14s -bash root pts/2 192.168.1.17 19:48 60.00s 0.05s 0.05s -bash
2. Use the who command to view (login) the user name and the started process
The who command is used to list the names of users currently logged in to the system. The output is: user name, tty number, time and date, and host address.
The who command in Linux is used to display which users are on the system. The displayed information includes user ID, terminal used, where they are connected from, online time, latency, and CPU Usage, actions, etc.
Syntax:
who [参数]
You can know which users are currently logged in to the system. Executing the who command alone will list the login account, the terminal used, the login time and where to log in from or currently in use. Which X monitor.
Parameters:
-H or --heading Display the title information column of each column.
-i or -u or --idle Display the idle time. If the user has performed any action within the previous minute, it will be marked with a "." symbol. If the user has performed any action within the past minute, it will be marked with a "." If there has been no action for more than 24 hours, the "old" string is marked.
#-m The effect of this parameter is the same as specifying the "ami" string.
-q or --count Only display the account names and total number of people logged into the system.
-s This parameter will be ignored and will not be processed. It is only responsible for solving the compatibility issues of other versions of the who directive.
-w or -T or --mesg or --message or --writable Display the user's information status bar.
#-l List any login processes.
-T or -w Display the user's information status bar.
The example is as follows: Display the user currently logged in to the system
[root@localhost ~]# who root tty2 2021-05-20 09:20 (tty2)
Recommended learning: Linux video tutorial
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