linux man page for get_phys_pages

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

NAME
       get_phys_pages, get_avphys_pages - get total and available physical page counts

SYNOPSIS
       #include <sys/sysinfo.h>

       long int get_phys_pages(void);
       long int get_avphys_pages(void);

DESCRIPTION
       The function get_phys_pages() returns the total number of physical pages of memory available on the system.

       The function get_avphys_pages() returns the number of currently available physical pages of memory on the system.

RETURN VALUE
       On  success,  these functions return a nonnegative value as given in DESCRIPTION.  On failure, they return -1 and set errno to indicate the
       cause of the error.

ERRORS
       ENOSYS The system could not provide the required information (possibly because the /proc filesystem was not mounted).

CONFORMING TO
       These functions are GNU extensions.

NOTES
       These functions obtain the required information by scanning the MemTotal and MemFree fields of /proc/meminfo.

       The following sysconf(3) calls provide a portable means of obtaining the same information as the functions described on this page.

	   total_pages = sysconf(_SC_PHYS_PAGES);    /* total pages */
	   avl_pages = sysconf(_SC_AVPHYS_PAGES);    /* available pages */

EXAMPLE
       The following example shows how get_phys_pages() and get_avphys_pages() can be used.

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

       int
       main(int argc, char *argv[])
       {
	   printf("This system has %ld pages of physical memory and "
		   "%ld pages of physical memory available.
",
		   get_phys_pages(), get_avphys_pages());
	   exit(EXIT_SUCCESS);
       }

SEE ALSO
       sysconf(3)

GNU
								    2019-03-06							 GET_PHYS_PAGES(3)