Solution to CentOS ── xxx is not in the sudoers file Method

Solution to CentOS ── xxx is not in the sudoers file Method
Compared to the previous one, CentOS was selected as the Linux system. Just installed into the virtual machine, the system permission cannot be enabled by default. After entering sudo in the terminal, the system prompts "XXX is not in the sudoers file. this incident will be reported. "Search for the Internet and find a solution: when using sudo, the system prompts" xxx is not in the sudoers file. this incident will be reported. XXX is your user name, that is, your user name does not have permission to use sudo. You just need to modify the/etc/sudoers file. The following is the modification method:

1) enter the superuser mode. That is, enter "su-". The system will ask you to enter the superuser password and enter the password to enter the superuser mode. (Of course, you can also use root)
2) Add the write permission for the file. That is, enter the command "chmod u + w/etc/sudoers ".
3) edit the/etc/sudoers file. That is, enter the command "vim/etc/sudoers", enter "I" to enter the editing mode, and find this line: "root ALL = (ALL) ALL "add" xxx ALL = (ALL) ALL "(here xxx is your user name), and save it (that is, press the Esc key first, and then enter ": wq ") quit.


4) revoke the write permission of a file. That is, enter the command "chmod u-w/etc/sudoers"