getpriority.2 (2010 09)

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getpriority(2) getpriority(2)
NAME
getpriority, setpriority - get or set process priority
SYNOPSIS
#include <sys/resource.h>
int getpriority(int which, int who);
int setpriority(int which, int who, int priority);
DESCRIPTION
getpriority()
returns the priority of the indicated processes.
setpriority()
sets the priority of the indicated processes to priority .
The processes are indicated by which and who, where which can have one of the following values:
PRIO_PROCESS Get or set the priority of the specified process where who is the process ID. A
who of
0 implies the process ID of the calling process.
PRIO_PGRP Get or set the priority of the specified process group where who is the process-
group ID, indicating all processes belonging to that process-group. A who of
0
implies the process-group ID of the calling process.
PRIO_USER Get or set the priority of the specified user where who is the user ID, indicat-
ing all processes owned by that user. A who of 0 implies the user ID of the
calling process.
If more than one process is indicated, the value returned by
getpriority()
is the lowest valued prior-
ity of all the indicated processes, and
setpriority()
sets the priority of all indicated processes.
priority is a value from
-20 to 20, where lower values indicate better priorities. The default priority for
a process is 0.
If the calling process contains more than one thread or lightweight process (i.e., the process is multi-
threaded) these functions shall apply to all threads or lightweight processes in the calling process. The
priority specified (or retrieved) is the same for all threads or lightweight processes in a process. Negative
priorities require appropriate privileges.
Security Restrictions
These system calls are subject to compartmental restrictions which restrict their access to processes in
other compartments. This restriction covers
getpriority for querying the priority of processes in
other compartments, and
setpriority
for changing the priority of processes in other compartments.
See compartments (5) for more information about compartmentalization on systems that support that
feature.
Compartmental restrictions can be overridden if the process has the
COMMALLOWED privilege
(PRIV_COMMALLOWED). Processes owned by the superuser may not have this privilege. Processes
owned by any user may have this privilege, depending on system configuration.
setpriority requires the OWNER privilege (PRIV_OWNER) to change the priority of a process whose
uid does not match the caller’s real or effective uid.. Processes owned by the superuser have this
privilege. Processes owned by other users may have this privilege, depending on system configuration.
setpriority requires the LIMIT privilege (PRIV_LIMIT). Processes owned by the superuser have
this privilege. Processes owned by other users may have this privilege, depending on system
configuration.
RETURN VALUE
getpriority() returns the following values:
n Successful completion. n is an integer priority in the range
-20 to 20.
-1 Failure. errno is set to indicate the error. See WARNINGS below.
setpriority() returns the following values:
0 Successful completion.
-1 Failure. errno is set to indicate the error.
HP-UX 11i Version 3: September 2010 − 1 − Hewlett-Packard Company 1