[Ubuntu] sudo command not found

$ visudo

#
# 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"

用visudo編輯sudo設定，可以看到env_reset和secure_path變數，就是這個蓋掉了原來的設定
若不想修改sudo原有的設定，可以用下面方式
sudo -E env "PATH=$PATH" [指令] .....

可以用aliias的方式簡化使用 alias mysudo='sudo -E env "PATH=$PATH"'