What does su mean in linux?

In Linux, su is the abbreviation of "switch user", which means switching users. The su command is used to change the identity of another user. The syntax is "su option [USER [ARG]]"; When using this command, in addition to root, you need to enter the password of the user.

#The operating environment of this tutorial: linux7.3 system, Dell G3 computer.

#What does su mean in Linux

Linux su (English full spelling: switch user) command is used to change the identity of another user , except root, you need to enter the user's password.

Usage permissions: all users.

Syntax

su [-fmp] [-c command] [-s shell] [--help] [--version] [-] [USER [ARG]]

Parameter description:

• -f or --fast does not need to read the startup file (such as csh.cshrc, etc.), just use Do not change the environment variables when executing su in csh or tcsh

• -m -p or --preserve-environment

• -c command or- -command=command Change to the user whose account is USER and execute the command (command) and then change back to the original user

• -s shell or --shell=shell Specify what to execute shell (bash csh tcsh, etc.), the default value is the user (USER) in /etc/passwd shell

• --help Display description file

• --version Display version information

• - After adding -l or --login this parameter, it will be like logging in to the user again. Most of the time The environment variables (HOME SHELL USER, etc.) are based on the user (USER), and the working directory will also change. If USER is not specified, the default is root

• USER. Changed user account

• ARG Pass in new shell parameters

Example

Change the account to root and execute Exit and return to the original user after executing the ls command

su -c ls root

Change the account to root and pass the -f parameter to the newly executed shell

su root -f

Change the account to clsung and change the working directory to the home of clsung Directory (home dir)

su - clsung

Switch user

hnlinux@runoob.com:~$ whoami //显示当前用户
hnlinux
hnlinux@runoob.com:~$ pwd //显示当前目录
/home/hnlinux
hnlinux@runoob.com:~$ su root //切换到root用户
密码： 
root@runoob.com:/home/hnlinux# whoami 
root
root@runoob.com:/home/hnlinux# pwd
/home/hnlinux

Switch user, change environment variables

hnlinux@runoob.com:~$ whoami //显示当前用户
hnlinux
hnlinux@runoob.com:~$ pwd //显示当前目录
/home/hnlinux
hnlinux@runoob.com:~$ su - root //切换到root用户
密码： 
root@runoob.com:/home/hnlinux# whoami 
root
root@runoob.com:/home/hnlinux# pwd //显示当前目录
/root

Related recommendations: "Linux Video Tutorial"

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