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.\n",
            get_phys_pages(), get_avphys_pages());
    exit(EXIT_SUCCESS);
}

SEE ALSO¶

sysconf(3)

COLOPHON¶

This page is part of release 4.10 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/.