Ubuntu 20.04 添加当前用户 Root 权限

 karl@karl-pc:~$ sudo chmod +w /etc/sudoers

[sudo] password for karl: 
karl@karl-pc:~$ sudo vi /etc/sudoers

[1]+ Stopped sudo vi /etc/sudoers
karl@karl-pc:~$ sudo vi /etc/sudoers
karl@karl-pc:~$ sudo cat /etc/sudoers
#
# This file MUST be edited with the 'visudo' command as root.
#
# Please consider adding local content in /etc/sudoers.d/ instead of
# directly modifying this file.
#
# See the man page for details on how to write a sudoers file.
#
Defaults    env_reset
Defaults    mail_badpass
Defaults    secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin"

# Host alias specification

# User alias specification

# Cmnd alias specification

# User privilege specification
root    ALL=(ALL:ALL) ALL
karl    ALL=(ALL:ALL) ALL
# Members of the admin group may gain root privileges
%admin ALL=(ALL) ALL

# Allow members of group sudo to execute any command
%sudo    ALL=(ALL:ALL) ALL

# See sudoers(5) for more information on "#include" directives:

#includedir /etc/sudoers.d
karl@karl-pc:~$ sudo chmod -w /etc/sudoers