To change the priority of a currently running process, which command would you use?

To change the priority of a currently running process, the correct command is "renice." This command allows you to alter the scheduling priority of an existing process. The priority value, known as the "niceness" level, can be increased (to make the process less favorable in terms of CPU scheduling) or decreased (to give it more favorable treatment).

When you use "renice," you provide the new niceness value followed by the process identifiers (PIDs) of the processes you wish to modify. For example, using renice 10 -p 1234 would change the niceness of the process with PID 1234 to 10.

In contrast, the command “nice” is typically used to start a new process with a specific niceness level, rather than modifying an already running process. “priority” and “chprio” are not standard commands in Linux for modifying process priorities and may not be recognized in many Linux distributions.