bsd man page for nice

NICE(3C)																  NICE(3C)

NAME
       nice - set program priority

SYNOPSIS
       nice(incr)

DESCRIPTION
       This interface is obsoleted by setpriority(2).

       The scheduling priority of the process is augmented by incr.  Positive priorities get less service than normal.	Priority 10 is recommended
       to users who wish to execute long-running programs without flak from the administration.

       Negative increments are ignored except on behalf of the super-user.  The priority is limited to the range -20 (most urgent) to 20 (least).

       The priority of a process is passed to a child process by fork(2).  For a privileged process to return to normal priority from  an  unknown
       state,  nice  should  be  called successively with arguments -40 (goes to priority -20 because of truncation), 20 (to get to 0), then 0 (to
       maintain compatibility with previous versions of this call).

SEE ALSO
       nice(1), setpriority(2), fork(2), renice(8)

4th Berkeley Distribution					    May 9, 1985 							  NICE(3C)