How to Run ‘sudo’ Command Without Entering a Password in Linux

In case you are running Linux on a machine that you normally use alone, say on a laptop, entering a password each time you invoke sudo can become so boring in the long run. Therefore, in this guide, we will describe how to configure sudo command to run without entering a password.

This setting is done in the /etc/sudoers file, which drives sudoers to use default security policy plugin for the sudo command; under the user privilege specification section.

Important: In the sudeors file, the authenticate parameter which is turned on by default is used for authentication purposes. If it is set, users must authenticate themselves via a password (or other means of authentication) before they run commands with sudo.

However, this default value may be overridden using the NOPASSWD (require no password when user invokes sudo command) tag.

The syntax to configure user privileges is as follows:

user_list host_list=effective_user_list tag_list command_list

Where:

1. user_list – list of users or a user alias that has already been set.
2. host_list – list of hosts or a host alias on which users can run sudo.
3. effective_user_list – list of users they must be running as or a run as alias.
4. tag_list – list of tags such as NOPASSWD.
5. command_list – list of commands or a command alias to be run by user(s) using sudo.

To allow a user (aaronkilik in the example below) to run all commands using sudo without a password, open the sudoers file:

$ sudo visudo

And add the following line:

aaronkilik ALL=(ALL) NOPASSWD: ALL

For the case of a group, use the % character before the group name as follows; this means that all member of the sys group will run all commands using sudo without a password.

%sys ALL=(ALL) NOPASSWD: ALL

To permit a user to run a given command (/bin/kill) using sudo without a password, add the following line:

aaronkilik ALL=(ALL) NOPASSWD: /bin/kill

The line below will enable member of the sys group to run the commands: /bin/kill, /bin/rm using sudo without a password:

%sys ALL=(ALL) NOPASSWD: /bin/kill, /bin/rm

For more sudo configuration and additional usage options, read our articles that describes more examples:

1. 10 Useful Sudoers Configurations for Setting ‘sudo’ in Linux
3. Let Sudo Insult You When You Enter Incorrect Password
4. How to Keep ‘sudo’ Password Timeout Session Longer in Linux

In this article, we described how to configure sudo command to run without entering a password. Do not forget to offer us your thoughts about this guide or other useful sudeors configurations for Linux system administrators all in the comments.