


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
The above is the detailed content of How to check how many users are logged in in Linux. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undress AI Tool
Undress images for free

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

Informix and MySQL are both popular relational database management systems. They perform well in Linux environments and are widely used. The following is a comparison and analysis of the two on the Linux platform: Installing and configuring Informix: Deploying Informix on Linux requires downloading the corresponding installation files, and then completing the installation and configuration process according to the official documentation. MySQL: The installation process of MySQL is relatively simple, and can be easily installed through system package management tools (such as apt or yum), and there are a large number of tutorials and community support on the network for reference. Performance Informix: Informix has excellent performance and

To tune MySQL into a Chinese interface, it can be implemented through MySQLWorkbench or command line tools. 1) In MySQLWorkbench, open "Preferences", select the "Appearance" tab, and then select "Chinese(Simplified)" in the "Language" drop-down menu, and restart. 2) When using command line tools, set the operating system locale variables, such as using "exportLANG=zh_CN.UTF-8" on Linux or macOS, and then run the mysql client.

Linux and Windows have their own advantages and disadvantages in CPU and memory usage: 1) Linux uses time slice-based scheduling algorithms to ensure fairness and efficiency; Windows uses priority scheduling, which may cause low-priority processes to wait. 2) Linux manages memory through paging and switching mechanisms to reduce fragmentation; Windows tends to pre-allocate and dynamic adjustment, and efficiency may fluctuate.

Linux's cost of ownership is usually lower than Windows. 1) Linux does not require license fees, saving a lot of costs, while Windows requires purchasing a license. 2) Linux has low hardware requirements and can extend the service life of the device. 3) The Linux community provides free support to reduce maintenance costs. 4) Linux is highly secure and reduces productivity losses. 5) The Linux learning curve is steep, but Windows is easier to use. The choice should be based on specific needs and budget.

LinuxoftenoutperformsWindowsinI/Operformanceduetoitscustomizablekernelandfilesystems,whileWindowsoffersmoreuniformperformanceacrosshardware.1)LinuxexcelswithcustomizableI/OschedulerslikeCFQandDeadline,enhancingperformanceinhigh-throughputapplications

The key to installing dual systems in Linux and Windows is partitioning and boot settings. 1. Preparation includes backing up data and compressing existing partitions to make space; 2. Use Ventoy or Rufus to make Linux boot USB disk, recommend Ubuntu; 3. Select "Coexist with other systems" or manually partition during installation (/at least 20GB, /home remaining space, swap optional); 4. Check the installation of third-party drivers to avoid hardware problems; 5. If you do not enter the Grub boot menu after installation, you can use boot-repair to repair the boot or adjust the BIOS startup sequence. As long as the steps are clear and the operation is done properly, the whole process is not complicated.

The key to enabling EPEL repository is to select the correct installation method according to the system version. First, confirm the system type and version, and use the command cat/etc/os-release to obtain information; second, enable EPEL through dnfinstallepel-release on CentOS/RockyLinux, and the 8 and 9 version commands are the same; third, you need to manually download the corresponding version of the .repo file and install it on RHEL; fourth, you can re-import the GPG key when encountering problems. Note that the old version may not be supported, and you can also consider enabling epel-next to obtain the test package. After completing the above steps, use dnfrepolist to verify that the EPEL repository is successfully added.

Linux usually performs better in web server performance, mainly due to its advantages in kernel optimization, resource management and open source ecosystem. 1) After years of optimization of the Linux kernel, mechanisms such as epoll and kqueue make it more efficient in handling high concurrent requests. 2) Linux provides fine-grained resource management tools such as cgroups. 3) The open source community continuously optimizes Linux performance, and many high-performance web servers such as Nginx are developed on Linux. By contrast, Windows performs well when handling ASP.NET applications and provides better development tools and commercial support.
