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(), get_nprocs_conf()                                │ Thread safety │ MT-Safe │
       └───────────────────────────────────────────────────────────────┴───────────────┴─────────┘

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 */

EXAMPLES

       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 5.13 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/.