This article is mainly about explanation and demonstration Linux In the system su Command usage and common usage .
Linux su Use case of command
su Commands are also called switch user, Switch users . This command is used to switch the user's identity to another user during the login session . When no switch target user name is specified ,su Default switch to root user . Normally ,su The command is used to switch the currently logged in user to another user without exiting the system .
This is a Linux Commands often used by end users . This tutorial will help you understand through use cases Linux su command reference .
su [OPTIONS] [USER] [OPTIONAL ARGS...]
2. `su` Command usage example
Let's start with a simple demonstration . I use zcwyou The user login Linux System , Use whoami The command verifies the identity . And then use su Command switch to root user . Verified the identity again .
Switch to root user
su - root
Re execution whoami
Output results ：
su Command usage example
Supplementary knowledge :
- If you don't specify a user name ,su By default, it switches to root.
- Use hyphens (-) Switch environment variables .
sudo Privileged users can also be in sudo with su command . Such as :
sudo su - root
su Command switch user
occasionally , You may just need to switch users to run one or more commands . under these circumstances ,su The order provides -c Options , You can call another user to run the command , Without actually switching shell.
Try this command ：
Execute the following command on a regular account ：
su - root -c "whoami"
Input root After the password , Output the following results
su Command line options ：
Linux su Command options are few but useful . These options are in use shell Scripts are very useful for automating tasks .
- 1. -c： To execute a command as a user .
- 2. - -l, --login： Login user account , Use the new user's environment variables .
- 3. -s, --shell： Appoint shell, Do not press /etc/passwd The default... Specified in the file shell perform .
- 4. -m, -p, --preserve-environment： Keep existing environment variables , This is useful for temporarily borrowing other users to execute commands , Very useful .
su Command common options
Through this tutorial , You should know that Linux su The use of command and common usage ？ Actually su The command function is simple , It's used to switch user identities . If you have any questions , Please leave a message .
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