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

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.
",
		   get_nprocs_conf(), get_nprocs());
	   exit(EXIT_SUCCESS);
       }

SEE ALSO

       nproc(1)

COLOPHON

       This  page is part of release 4.15 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
								    2017-09-15							     GET_NPROCS(3)