nice(2) [hpux man page]
nice(2) System Calls Manual nice(2) NAME
nice - change priority of a process SYNOPSIS
DESCRIPTION
adds the value of priority_change to the nice value of the calling process. A process's is a positive number for which a more positive value results in lower CPU priority. A maximum nice value of 39 and a minimum nice value of 0 are imposed by the system. Requests for values above or below these limits result in the nice value being set to the corresponding limit. If the calling process contains more than one thread or lightweight process (i.e., the process is multi-threaded) this function shall apply to all threads or lightweight processes in the calling process. Security Restrictions Some or all of the actions associated with this system call are subject to compartmental restrictions. See compartments(5) for more infor- mation about compartmentalization on systems that support that feature. Compartmental restrictions can be overridden if the process pos- sesses the privilege (COMMALLOWED). Processes owned by the superuser may not have this privilege. Processes owned by any user may have this privilege, depending on system configuration. Some or all of the actions associated with this system call require the (OWNER) and/or the (LIMIT) privileges. Processes owned by the superuser will have these privileges. Processes owned by other users may have privilege(s), depending on system configuration. See privi- leges(5) for more information about privileged access on systems that support fine-grained privileges. RETURN VALUE
Upon successful completion, returns the new nice value minus 20. Otherwise, a value of -1 is returned and is set to indicate the error. Note that assumes a user process priority value of 20. If a user having appropriate privileges has changed the user process priority value to something less than 20, certain values for priority_change can cause to return -1, which is indistinguishable from an error return. ERRORS
[EPERM] fails and does not change the nice value if priority_change is negative or greater than 40, and the effective user ID of the calling process is not a user having appropriate privileges. SEE ALSO
nice(1), renice(1M), exec(2), privileges(5). STANDARDS CONFORMANCE
nice(2)
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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)