Operation and Maintenance
Linux Operation and Maintenance
How to create a user and specify a user group in Linux
How to create a user and specify a user group in Linux
linuxCreate a user and specify a user group
1. View all users
cat /etc/passwd
groupadd zhangsangroup #创建用户组zhangsangroup
useradd -g zhangsan zhangsan 创建用户zhangsan并加入zhangsangroup组
useradd parameters:
-u UID
: Specify UID, this UID must be greater than or equal to 500, and there is no UID occupied by other users-g GID
/GROUPNAME: Specify the default group, which can be GID or GROUPNAME, and must also exist-G GROUPS
: Specify additional groups-c COMMENT
: Specify the user’s comment information-d PATH
: Specify the user’s home directory
useradd user3 #新增用户 usermod –l u1 user1 #将用户user1的登录名改为u1 usermod –d /users/us1 user1 #将用户 user1家目录改为/users/us1 usermod –g users user1 #将用户user1加入到 users组中， userdel user3 #删除用户 userdel –r user3 #删除用户并删除家目录 groupadd users #添加一个用户组users groupmod –n user users #修改组名user为users groupdel users 删除组users# The
- ##id
command can view the UID and GID of a user, for example: id user4
- finger
command can view the user’s main Directory, startup shell, user name, address, phone number and other information. Example: finger user4
##groups - command to view the groups to which the user belongs, for example: groups root
2. Use the gpasswd command to add users to the group.
gpasswd –a user1 users #把 user1加入users组 gpasswd –d user1 users #把 user1退出users组3. Modify file permissions chmod
chmod -R 777 /var/lib/mysql #表示修改文件为最高权限-R means processing all files in the specified directory and its subdirectories4. Modify the user and group chown of the file (note: the owner is first, the group is last)
chown -R mysql:mysql /var/lib/mysqlFormat: chown [option]...[owner][:[group]] File...-R means to process all files in the specified directory and its subdirectorieslinuxCreate a user and determine the group the user belongs to1. Create the group monster
[root@zhz home]# groupadd monster
2. Create the user tom, and the group tom belongs to is monster[root@zhz home]# useradd -g monster tom
The above is the detailed content of How to create a user and specify a user group 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)
How to install software on Linux using the terminal?
Aug 02, 2025 pm 12:58 PM
There are three main ways to install software on Linux: 1. Use a package manager, such as apt, dnf or pacman, and then execute the install command after updating the source, such as sudoaptininstallcurl; 2. For .deb or .rpm files, use dpkg or rpm commands to install, and repair dependencies when needed; 3. Use snap or flatpak to install applications across platforms, such as sudosnapinstall software name, which is suitable for users who are pursuing version updates. It is recommended to use the system's own package manager for better compatibility and performance.
The Ultimate Guide to High-Performance Gaming on Linux
Aug 03, 2025 am 05:51 AM
ChoosePop!_OS,Ubuntu,NobaraLinux,orArchLinuxforoptimalgamingperformancewithminimaloverhead.2.InstallofficialNVIDIAproprietarydriversforNVIDIAGPUs,ensureup-to-dateMesaandkernelversionsforAMDandIntelGPUs.3.EnabletheperformanceCPUgovernor,usealow-latenc
What are the main pros and cons of Linux vs. Windows?
Aug 03, 2025 am 02:56 AM
Linux is suitable for old hardware, has high security and is customizable, but has weak software compatibility; Windows software is rich and easy to use, but has high resource utilization. 1. In terms of performance, Linux is lightweight and efficient, suitable for old devices; Windows has high hardware requirements. 2. In terms of software, Windows has wider compatibility, especially professional tools and games; Linux needs to use tools to run some software. 3. In terms of security, Linux permission management is stricter and updates are convenient; although Windows is protected, it is still vulnerable to attacks. 4. In terms of difficulty of use, the Linux learning curve is steep; Windows operation is intuitive. Choose according to requirements: choose Linux with performance and security, and choose Windows with compatibility and ease of use.
Understanding RAID Configurations on a Linux Server
Aug 05, 2025 am 11:50 AM
RAIDimprovesstorageperformanceandreliabilityonLinuxserversthroughvariousconfigurations;RAID0offersspeedbutnoredundancy;RAID1providesmirroringforcriticaldatawith50�pacityloss;RAID5supportssingle-drivefailuretoleranceusingparityandrequiresatleastthre
Linux how to enable and disable services at boot
Aug 08, 2025 am 10:23 AM
To manage the startup of Linux services, use the systemctl command. 1. Check the service status: systemctlstatus can check whether the service is running, enabled or disabled. 2. Enable the service startup: sudosystemctlenable, such as sudosystemctlenablenginx. If it is started at the same time, use sudosystemctlenable--nownginx. 3. Disable the service startup: sudosystemctldisable, such as sudosystemctldisablecups. If it is stopped at the same time, use sudosystemctldisabl
Linux how to list all running processes
Aug 08, 2025 am 06:42 AM
Usepsauxforacompletesnapshotofallrunningprocesses,showingdetailedinformationlikeUSER,PID,CPU,andmemoryusage.2.Usetoporhtopforreal-timemonitoringofprocesseswithdynamicupdates,wherehtopoffersamoreintuitiveinterface.3.UsepgreporpidoftoquicklyfindthePIDs
How to clean up your Linux system
Aug 22, 2025 am 07:42 AM
Removeunusedpackagesanddependencieswithsudoaptautoremove,cleanpackagecacheusingsudoaptcleanorautoclean,andremoveoldkernelsviasudoaptautoremove--purge.2.Clearsystemlogswithsudojournalctl--vacuum-time=7d,deletearchivedlogsin/var/log,andempty/tmpand/var
Linux how to view the contents of a file
Aug 19, 2025 pm 06:44 PM
ToviewfilecontentsinLinux,usedifferentcommandsbasedonyourneeds:1.Forsmallfiles,usecattodisplaytheentirecontentatonce,withcat-ntoshowlinenumbers.2.Forlargefiles,uselesstoscrollpagebypageorlinebyline,searchwith/search_term,andquitwithq.3.Usemoreforbasi
