.\" Copyright (c) 1980 The Regents of the University of California.
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.\" @(#)getpriority.2 6.7 (Berkeley) %G%
getpriority, setpriority \- get/set program scheduling priority
#include <sys/resource.h>
prio = getpriority(which, who)
setpriority(which, who, prio)
priority of the process, process group, or user, as indicated by
is one of PRIO_PROCESS, PRIO_PGRP, or PRIO_USER, and
is interpreted relative to
(a process identifier for PRIO_PROCESS, process group
identifier for PRIO_PGRP, and a user ID for PRIO_USER).
denotes the current process, process group, or user.
is a value in the range \-20 to 20. The default priority is 0;
lower priorities cause more favorable scheduling.
call returns the highest priority (lowest numerical value)
enjoyed by any of the specified processes. The
call sets the priorities of all of the specified processes
to the specified value. Only the super-user may lower priorities.
can legitimately return the value \-1, it is necessary
to clear the external variable \fIerrno\fP prior to the
call, then check it afterward to determine
if a \-1 is an error or a legitimate value.
call returns 0 if there is no error, or
may return one of the following errors:
No process was located using the
was not one of PRIO_PROCESS, PRIO_PGRP, or PRIO_USER.
In addition to the errors indicated above,
may fail with one of the following errors returned:
A process was located, but neither its effective nor real user
ID matched the effective user ID of the caller.
A non super-user attempted to lower a process priority.
nice(1), fork(2), renice(8)