Force who parameters to be interpreted as process group ID’s.
-n
Instead of changing the specified processes to the given priority, interpret the following argument as an increment to be applied to the current priority of each process.
-u
Force the who parameters to be interpreted as user names or user ID’s.
-p
Reset the who interpretation to be (the default) process ID’s.
For example,
"renice +1 987 -u daemon root -p 32"
would change the priority of process ID’s 987 and 32, and all processes owned by users daemon and root.
Users other than the super-user may only alter the priority of processes they own, and can only monotonically increase their ‘‘nice value’’ within the range 0 to PRIO_MAX (20). (This prevents overriding administrative fiats.) The super-user may alter the priority of any process and set the priority to any value in the range PRIO_MIN (-20) to PRIO_MAX. Useful priorities are: 20 (the affected processes will run only when nothing else in the system wants to), 0 (the ‘‘base’’ scheduling priority), anything negative (to make things go very fast).
