描述：用户在sudo一个命令的时候必须输入root密码。用起来比较麻烦。

解决：输入命令"vim /etc/sudoers",输入"i"进入编辑模式，找到这一 行："root ALL=(ALL) ALL"在起下面添加"xxx ALL=(ALL) NOPASSWD: ALL "(这里的xxx是你的用户名)，然后在末行模式输入：:w !sudo tee %最后保存：q。

测试是否成功：

[liu@localhost Desktop]$ sudo

usage: sudo -h | -K | -k | -L | -V

usage: sudo -v [-AknS] [-g groupname|#gid] [-p prompt] [-u user name|#uid]

usage: sudo -l[l] [-AknS] [-g groupname|#gid] [-p prompt] [-U user name] [-u

            user name|#uid] [-g groupname|#gid] [command]

usage: sudo [-AbEHknPS] [-r role] [-t type] [-C fd] [-g groupname|#gid] [-p

            prompt] [-u user name|#uid] [-g groupname|#gid] [VAR=value] [-i|-s]

            [<command>]

usage: sudo -e [-AknS] [-r role] [-t type] [-C fd] [-g groupname|#gid] [-p

            prompt] [-u user name|#uid] file ...