How to add a user and give the user root access under Linux

Transferred from: http://blog.sina.com.cn/s/blog_6fc583e70100n6rm.html

Test environment: CentOS 5.5

1, add the user, first with the AddUser command to add a normal user, the command is as follows:

Add a user named Tommy #passwd Tommy   //Change password for Tommy.  Password//Enter a new password here password//Enter the new password successfully again.        

2. Give root permission

Method One: Modify the/etc/sudoers file, locate the following line, remove the previous comment (#)

# # allows people in group wheel to run all commands%wheel all    =(   All 

Then modify the user to belong to the root group (wheel) with the following command:

#usermod-G root Tommy

After the modification, you can now log in with your Tommy account, and then use the command Su-to get root privileges to operate.

Method Two: Modify the/etc/sudoers file, locate the following line, and add a line under root as follows:

# allow ROOT to run any commands anywhereroot all                All

After the modification, you can now log in with your Tommy account, and then use the command Su-to get root privileges to operate.

Method Three: Modify the/etc/passwd file, locate the following line, change the user ID to 0, as follows:

Tommy: x: £ º:Tommy:/home/tommy:/bin/bash 

Modified as follows

Tommy:x:0::Tommy:/home/tommy:/bin/bash   

Save, with Tommy account login, directly get the root account permissions.

Friendly reminder: Although method three looks simple and convenient, but generally not recommended use, recommended method two.

How to add a user and give the user root access under Linux