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28 .\" @(#)getpriority.2 8.1 (Berkeley) 6/4/93
29 .\" $FreeBSD: src/lib/libc/sys/getpriority.2,v 1.4.2.5 2001/12/14 18:34:00 ru Exp $
30 .\" $DragonFly: src/lib/libc/sys/getpriority.2,v 1.3 2008/05/01 23:36:43 swildner Exp $
38 .Nd get/set program scheduling priority
45 .Fn getpriority "int which" "int who"
47 .Fn setpriority "int which" "int who" "int prio"
50 priority of the process, process group, or user, as indicated by
67 is interpreted relative to
69 (a process identifier for
78 denotes the current process, process group, or user.
80 is a value in the range -20 to 20. The default priority is 0;
81 lower priorities cause more favorable scheduling.
85 call returns the highest priority (lowest numerical value)
86 enjoyed by any of the specified processes. The
88 call sets the priorities of all of the specified processes
89 to the specified value. Only the super-user may lower priorities.
93 can legitimately return the value -1, it is necessary
94 to clear the external variable
97 call, then check it afterward to determine
98 if a -1 is an error or a legitimate value.
108 No process was located using the
122 In addition to the errors indicated above,
127 A process was located, but neither its effective nor real user
128 ID matched the effective user ID of the caller.
130 A non super-user attempted to lower a process priority.
139 function call appeared in