GET_PHYS_PAGES

Section: Linux Programmer's Manual (3)
Updated: 2020-11-01
Page Index

NAME

get_phys_pages, get_avphys_pages - get total and available physical page counts

SYNOPSIS

#include <sys/sysinfo.h>

long get_phys_pages(void);
long 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 */

EXAMPLES

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); }

COLOPHON

This page is part of release 5.10 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/.