Name
get_nprocs, get_nprocs_conf - get number of processorsLibrary
Standard C library ( libc ", " -lc )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 |
T} | Thread safety | MT-Safe |
Standards
GNU.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 <stdio.h> #include <stdlib.h> #include <sys/sysinfo.h> int main(void) { printf("This system has %d processors configured and " "%d processors available.\en", get_nprocs_conf(), get_nprocs()); exit(EXIT_SUCCESS); }
See Also
- nproc(1)