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This article mainly introduces "the difference between su and sudu commands in linux". In daily operation, I believe many people have doubts about the difference between su and sudu commands in linux. Xiaobian consulted all kinds of information and sorted out simple and easy to use operation methods. I hope to answer the doubts of "the difference between su and sudu commands in linux"! Next, please follow the small series to learn together!

su and sudo user switching

su user switching, syntax:

su [-] USER_NAME

su - root Switch completely to the new user, without preserving environment variables, home directories, etc.

su root semi-switch, keep old user environment variables, home directory, etc., run process only as current user

Because su exposes the root password and is inconvenient for scripts to execute, sudo is available.

sudo has a data file, only users in the file can execute sudo

Syntax: sudo COMMAND, for example:

$ sudo iotop Run iotop as root

I. Description of the data file:

/etc/sudoers record format

Authorized Users/Groups Host =[(Switch to which users or groups)] [Password authentication required] Command 1, Command 2,...

Field1 Field2 =[(Field3)] [Field4] Field5

Field 3 and field 4 can be omitted.

Field 3 is omitted for any user or group of the system

Possible values for field 4 are NOPASSWD: . The default omission requires a password, note that NOPASSWD is followed by a colon: . Sudo can be performed without a password. For example:

root ALL= ALL

zabbix ALL= NOPASSWD: ZABBIXCMD

xzl ALL= ALL

xzl ALL= NOPASSWD: ALL

User group: A collection of multiple users, defined if multiple users all execute the same command.

User group: /etc/group

User: /etc/passwd

Command Groups: Define multiple commands into a group

Cmnd_Alias ZABBIXCMD = /usr/sbin/ss, /usr/bin/systemctl restart httpd

zabbix ALL= NOPASSWD: ZABBIXCMD

It must be said: faults! visiblepw will define sudo to run only on tty terminals, not scripts, must comment

II. Description of common commands of sudo

-b: Execution of instructions in the background;

-h: Display help;

-k: End of password validity period, that is, the next time sudo is executed, you need to enter the password;

-l: List the current user executable instructions;

-s: Executes the specified shell;

-u: Run command as specified user.

sudo -l View commands that can be executed

sudo iotop -b -k -n 3 -o Run iotop as root

sudo -u zabbix sudo iotop -b -k -n 3 -o Check whether a user (zabbix) can run a command (iotop) Common

At this point, the study of "the difference between su and sudu commands in linux" is over, hoping to solve everyone's doubts. Theory and practice can better match to help you learn, go and try it! If you want to continue learning more relevant knowledge, please continue to pay attention to the website, Xiaobian will continue to strive to bring more practical articles for everyone!

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