get_phys_pages, get_avphys_pages — get total and available physical page counts


#include <sys/sysinfo.h>

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


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.



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

Conforming to

These functions are GNU extensions.


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 */


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>

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());

See Also



This page is part of release 5.04 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

Referenced By


The man page get_avphys_pages(3) is an alias of get_phys_pages(3).

2019-03-06 GNU Linux Programmer's Manual