|NICE(3)||Library Functions Manual||NICE(3)|
nice — change
process scheduling priority
nice() function adds the value
specified in incr to the scheduling priority of the
incr is an integer such that the resulting scheduling priority is within the range -20 to 20. Priority values outside this range are truncated to the appropriate limit. The default priority is 0; lower priorities cause more favorable scheduling. Only the superuser may lower priorities.
Children inherit the priority of their parent processes via fork(2).
nice() returns the new
priority. On error, it returns -1.
nice() can legitimately return the
value -1, it is necessary to clear the external variable
errno prior to the call, then check it afterward to
determine if a -1 is an error or a legitimate value.
nice() has the same failure conditions as
nice() system call first appeared in
Version 3 AT&T UNIX. It has accepted an
incr argument since Version 4
|July 18, 2013||OpenBSD-current|