NAME

       get_nprocs, get_nprocs_conf - get number of processors

SYNOPSIS

       #include <sys/sysinfo.h>

       int get_nprocs(void);
       int get_nprocs_conf(void);

DESCRIPTION

       The function get_nprocs_conf() returns the number of processors configured by the operating system.

       The  function  get_nprocs() returns the number of processors currently available in the system.  This may
       be less than the number returned by  get_nprocs_conf()  because  processors  may  be  offline  (e.g.,  on
       hotpluggable systems).

RETURN VALUE

       As given in DESCRIPTION.

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).
       ┌───────────────────┬───────────────┬─────────┐
       │ Interface         │ Attribute     │ Value   │
       ├───────────────────┼───────────────┼─────────┤
       │ get_nprocs(),     │ Thread safety │ MT-Safe │
       │ get_nprocs_conf() │               │         │
       └───────────────────┴───────────────┴─────────┘

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 filesystem 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(_SC_NPROCESSORS_CONF);     /* processors configured */
           np = sysconf(_SC_NPROCESSORS_ONLN);     /* processors available */

EXAMPLE

       The following example shows how get_nprocs() and get_nprocs_conf() can be used.

       #include <stdlib.h>
       #include <stdio.h>
       #include <sys/sysinfo.h>

       int
       main(int argc, char *argv[])
       {
           printf("This system has %d processors configured and "
                   "%d processors available.\n",
                   get_nprocs_conf(), get_nprocs());
           exit(EXIT_SUCCESS);
       }

SEE ALSO

       nproc(1)

COLOPHON

       This page is part of release 5.05 of  the  Linux  man-pages  project.   A  description  of  the  project,
       information   about   reporting   bugs,   and   the  latest  version  of  this  page,  can  be  found  at
       https://www.kernel.org/doc/man-pages/.

GNU                                                2019-03-06                                      GET_NPROCS(3)