getpriority(2) System Calls Manual getpriority(2)
NAME
getpriority, setpriority - get or set process priority
SYNOPSIS
DESCRIPTION
returns the priority of the indicated processes.
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:
Get or set the priority of the specified process where
who is the process ID. A who of implies the process ID of the calling process.
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 implies the
process-group ID of the calling process.
Get or set the priority of the specified user where
who is the user ID, indicating all processes owned by that user. A who of implies the user ID of the calling
process.
If more than one process is indicated, the value returned by is the lowest valued priority of all the indicated processes, and sets the
priority of all indicated processes.
priority is a value from to 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 restric-
tion covers for querying the priority of processes in other compartments, and 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 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.
requires the privilege (PRIV_OWNER) to change the priority of a process whose uid does not match the caller's real or effective uid.. Pro-
cesses owned by the superuser have this privilege. Processes owned by other users may have this privilege, depending on system configura-
tion.
requires the 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
returns the following values:
Successful completion.
n is an integer priority in the range to
Failure.
is set to indicate the error. See WARNINGS below.
returns the following values:
Successful completion.
Failure.
is set to indicate the error.
ERRORS
If or fails, is set to one of the following values:
[EACCES] The calling process does not have access rights to change one or more of the indicated processes. All processes for
which access is allowed are still affected.
[EINVAL] which is not one of the choices listed above, or who is out of range.
[EPERM] The calling process attempted to change the priority of a process to a smaller priority value without having appro-
priate privileges.
[ESRCH] Processes indicated by which and who cannot be found.
WARNINGS
can return both when it successfully finds a priority of and when it fails. To determine whether a failure occurred, set to before calling
then examine after the call returns.
AUTHOR
and were developed by the University of California, Berkeley.
SEE ALSO
nice(1), renice(1M), nice(2).
getpriority(2)