The //**sudo**// command in Linux and Unix-like systems like FreeBSD is used to execute a command with the privileges of another user, usually the superuser (root). It allows regular users to perform tasks that require root privileges, without logging out and logging back in as the root user. It is considered more secure than the **[[unix_commands:su|su]]** command as it provides a more fine-grained control over which users can run which commands.

Here are a few examples of how the **sudo** command can be used in //**Linux**// and //**FreeBSD**//:

  - Run a command as the superuser (root): **sudo command**
  - Run a command as a specific user: **sudo -u username command**
  - Run a command and preserve environment variables: **sudo -E command**

The **sudo** command without any options will prompt the user for their own password and run the command with the privileges of the superuser (root). The **-u** option is used to run a command as a specific user. The **-E** option is used to preserve environment variables when running the command. 

It's important to keep in mind that the use of **sudo** command in //**Linux**// is controlled by the //**/etc/sudoers**// file or by the configuration of the **sudo** plugin of the authentication mechanism in use. Generally, only those in the //**wheel**// group are able to elevate to superuser (root). For more information, please review the //**/etc/group**// file. The administrator has the control over who can use sudo and what commands they can run with it.

Please keep in mind that **sudo** is not installed by default in //**FreeBSD**//. You will need to install it using the port system or by using pkg_add first. Then, edit //**sudoers**// file located in ///**usr/local/etc/sudoers**//

It's also worth noting that using **sudo** command to run a command that modifies system files or settings, can have serious consequences if not done carefully, it's always a good idea to make a backup before making any changes and to test the command in a non-production environment first.