GETNPROCS(3) Linux Programmer's Manual GETNPROCS(3)

NAME
       getnprocs, getnprocsconf - get number of processors

SYNOPSIS
       #include 

       int getnprocs(void);
       int getnprocsconf(void);

DESCRIPTION
       The function getnprocsconf() returns the number of processors config‐
       ured by the operating system.

       The function getnprocs() returns the number  of  processors  currently
       available  in the system.  This may be less than the number returned by
       getnprocsconf() because processors may be offline (e.g., on  hotplug‐
       gable systems).

RETURN VALUE
       As given in DESCRIPTION.

CONFORMING TO
       These functions are GNU extensions.

NOTES
       The  current  implementation  of  these  functions is rather expensive,
       since they open and parse files in the /sys file system each time  they
       are called.

       The  following sysconf(3) calls make use of the functions documented on
       this page to return the same information.

           np = sysconf(SCNPROCESSORSCONF);     /* processors configured */
           np = sysconf(SCNPROCESSORSONLN);     /* processors available */

EXAMPLE
       The following example shows how getnprocs() and getnprocsconf()  can
       be used.

       #include 
       #include 

       int
       main(int argc, char *argv[])
       {
           printf("This system has %d processors configured and "
                   "%d processors available.\n",
                   getnprocsconf(), getnprocs());
           return 0;
       }


COLOPHON
       This  page  is  part of release 3.53 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.



GNU                               2012-03-20                     GETNPROCS(3)