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@(#)nice.3 8.1 (Berkeley) 6/4/93
$FreeBSD: stable/11/lib/libc/gen/nice.3 282008 2015-04-26 10:56:06Z bapt $
.Dd February 28, 2015 .Dt NICE 3 .Os .Sh NAME .Nm nice .Nd set program scheduling priority .Sh LIBRARY .Lb libc .Sh SYNOPSIS n unistd.h .Ft int .Fn nice "int incr" .Sh DESCRIPTION f -symbolic This interface is obsoleted by .Xr setpriority 2 . .Ef
p The .Fn nice function adds .Fa incr to the scheduling priority of the process. The priority is a value in the range -20 to 20. The default priority is 0; lower priorities cause more favorable scheduling. Only the super-user may lower priorities.
p Children inherit the priority of their parent processes via .Xr fork 2 . .Sh RETURN VALUES Upon successful completion, .Fn nice returns 0, and .Va errno is unchanged. Otherwise, -1 is returned, the process' nice value is not changed, and .Va errno is set to indicate the error. .Sh ERRORS The .Fn nice function will fail if: l -tag -width Er t Bq Er EPERM The .Fa incr argument is negative and the caller does not have appropriate privileges. .El .Sh SEE ALSO .Xr nice 1 , .Xr fork 2 , .Xr setpriority 2 , .Xr renice 8 .Sh STANDARDS The .Fn nice function conforms to .St -p1003.1-2008 except for the return value. This implementation returns 0 upon successful completion but the standard requires returning the new nice value, which could be -1. .Sh HISTORY A .Fn nice syscall appeared in .At v6 .