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.TH GET_PHYS_PAGES 3  2017-09-15 "GNU" "Linux Programmer's Manual"

.SH NAME

get_phys_pages, get_avphys_pages \- get total and available physical

page counts

.SH SYNOPSIS

.nf

.B "#include <sys/sysinfo.h>"

.PP

.B long int get_phys_pages(void);

.B long int get_avphys_pages(void);

.fi

.SH DESCRIPTION

The function

.BR get_phys_pages ()

returns the total number of physical pages of memory available on the system.

.PP

The function

.BR get_avphys_pages ()

returns the number of currently available physical pages of memory on the

system.

.SH RETURN VALUE

On success,

these functions return a nonnegative value as given in DESCRIPTION.

On failure, they return \-1 and set

.I errno

to indicate the cause of the error.

.SH ERRORS

.TP

.B ENOSYS

The system could not provide the required information

(possibly because the

.I /proc

filesystem was not mounted).

.SH CONFORMING TO

These functions are GNU extensions.

.SH NOTES

These functions obtain the required information by scanning the

.I MemTotal

and

.I MemFree

fields of

.IR /proc/meminfo .

.PP

The following

.BR sysconf (3)

calls provide a portable means of obtaining the same information as the

functions described on this page.

.PP

.in +4n

.EX

total_pages = sysconf(_SC_PHYS_PAGES);    /* total pages */

avl_pages = sysconf(_SC_AVPHYS_PAGES);    /* available pages */

.EE

.in

.SH EXAMPLE

The following example shows how

.BR get_phys_pages ()

and

.BR get_avphys_pages ()

can be used.

.PP

.EX

#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);

}

.EE

.SH SEE ALSO

.BR sysconf (3)

.SH COLOPHON

This page is part of release 4.15 of the Linux

.I 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/.