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Newer page: version 3 Last edited on Tuesday, December 31, 2002 1:45:33 am by PerryLorier
Older page: version 1 Last edited on Tuesday, June 4, 2002 12:23:41 am by perry Revert
@@ -1,111 +1,33 @@
-GETPRIORITY  
-!!!GETPRIORITY  
-NAME  
-SYNOPSIS  
-DESCRIPTION  
-RETURN VALUE  
-ERRORS  
-NOTE  
-CONFORMING TO  
-SEE ALSO  
-----  
 !!NAME 
-  
-  
- getpriority, setpriority - get/set program scheduling priority 
+getpriority - get program scheduling priority 
 !!SYNOPSIS 
+ __#include <sys/time.h>__  
+ __#include <sys/resource.h>__  
  
+ __int getpriority(int__ ''which''__, int__ ''who''__);__  
  
-__#include __  
-#include __  
-  
-  
-__int getpriority(int__ ''which''__, int__  
-''who''__);  
-int setpriority(int__ ''which''__, int__  
-''who''__, int__ ''prio''__);__  
 !!DESCRIPTION 
+The scheduling priority of the process, process group, or user, as indicated by ''which'' and ''who'' is obtained with the __getpriority__ call and set with the __setpriority__ call. ''Which'' is one of __PRIO_PROCESS__, __PRIO_PGRP__, or __PRIO_USER__,  
+and ''who'' is interpreted relative to ''which'' (a process identifier for __PRIO_PROCESS__, process group identifier for __PRIO_PGRP__, and a user ID for __PRIO_USER__). A zero value of ''who'' denotes the current process, process group, or user. ''Prio'' is a  
+value in the range -20 to 20. The default priority is 0; lower priorities cause more favorable scheduling.  
  
+The __getpriority__ call returns the highest priority (lowest numerical value) enjoyed by any of the specified processes. The __setpriority__ call sets the priorities of all of the specified processes to the specified value. Only the super-user may lower priorities.  
  
-The scheduling priority of the process, process group, or  
-user, as indicated by ''which'' and ''who'' is  
-obtained with the __getpriority__ call and set with the  
-__setpriority__ call. ''Which'' is one of  
-__PRIO_PROCESS__, __PRIO_PGRP__, or __PRIO_USER__,  
-and ''who'' is interpreted relative to ''which'' (a  
-process identifier for __PRIO_PROCESS__, process group  
-identifier for __PRIO_PGRP__, and a user ID for  
-__PRIO_USER__). A zero value of ''who'' denotes the  
-current process, process group, or user. ''Prio'' is a  
-value in the range -20 to 20. The default priority is 0;  
-lower priorities cause more favorable  
-scheduling.  
-  
-  
-The __getpriority__ call returns the highest priority  
-(lowest numerical value) enjoyed by any of the specified  
-processes. The __setpriority__ call sets the priorities  
-of all of the specified processes to the specified value.  
-Only the super-user may lower priorities.  
 !!RETURN VALUE 
+Since __getpriority__ can legitimately return the value -1, it is necessary to clear the external variable ''errno'' prior to the call, then check it afterwards to determine if a -1 is an error or a legitimate value. The __setpriority__ call returns 0 if there is no error, or -1 if there is.  
  
-  
-Since __getpriority__ can legitimately return the value  
--1, it is necessary to clear the external variable  
-''errno'' prior to the call, then check it afterwards to  
-determine if a -1 is an error or a legitimate value. The  
-__setpriority__ call returns 0 if there is no error, or  
--1 if there is.  
 !!ERRORS 
+;[ESRCH]: No process was located using the ''which'' and ''who'' values specified.  
+;[EINVAL]: ''Which'' was not one of __PRIO_PROCESS__, __PRIO_PGRP__, or __PRIO_USER__.  
  
-  
-__ESRCH__  
-  
-  
-No process was located using the ''which'' and ''who''  
-values specified.  
-  
-  
-__EINVAL__  
-  
-  
-''Which'' was not one of __PRIO_PROCESS__,  
-__PRIO_PGRP__, or __PRIO_USER__.  
-  
-  
-In addition to the errors indicated above,  
-__setpriority__ will fail if:  
-  
-  
-__EPERM__  
-  
-  
-A process was located, but neither its effective nor real  
-user ID matched the effective user ID of the  
-caller.  
-  
-  
-__EACCES__  
-  
-  
-A non super-user attempted to lower a process  
-priority.  
 !!NOTE 
+The actual priority range varies between kernel versions. Linux before 1.3.36 had -infinity..15. Linux since 1.3.43 has -20..19, and the system call getpriority returns 40..1 for these values (since negative numbers are error codes). The library call converts N into 20-N.  
  
+Including ''<sys/time.h>'' is not required these days, but increases portability. (Indeed, ''<sys/resource.h>'' defines the ''rusage''  
+structure with fields of type ''struct timeval'' defined in ''<sys/time.h>''.)  
  
-Including '''' is not required these  
-days, but increases portability. (Indeed,  
-'''' defines the ''rusage''  
-structure with fields of type ''struct timeval'' defined  
-in ''''.)  
 !!CONFORMING TO 
+SVr4, 4.4BSD (these function calls first appeared in 4.2BSD).  
  
-  
-SVr4, 4.4BSD (these function calls first appeared in  
-4.2BSD).  
 !!SEE ALSO 
-  
-  
- nice(1), fork(2),  
- renice(8 )  
-----  
+nice(1), fork(2), renice(1
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