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 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:
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.