renice - alter priority of running processes SYNOPSIS
Renice alters the scheduling priority of one or more running processes. The following who parameters are interpreted as process ID's, process group ID's, or user names. Renice'ing a process group causes all processes in the process group to have their scheduling priority altered. Renice'ing a user causes all processes owned by the user to have their scheduling priority altered. By default, the processes to be affected are specified by their process ID's.
would change the priority of process ID's 987 and 32, and all processes owned by users daemon and root.
to map user names to user ID's
Non super-users can not increase scheduling priorities of their own processes, even if they were the ones that decreased the priorities in the first place. The Linux kernel (at least version 2.0.0) and linux libc (at least version 5.2.18) does not agree entierly on what the specifics of the systemcall interface to set nice values is. Thus causes renice to report bogus previous nice values. HISTORY
The renice command appeared in 4.0 BSD .