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get_phys_pages

Section: C Library Functions (3)
Updated: 202-0-08
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NAME

get_phys_pages, get_avphys_pages - get total and available physical page counts

LIBRARY

Standard C library (libc,~-lc)

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 error.

ERRORS

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

STANDARDS

GNU.

HISTORY

Before glibc 2.23, these functions obtained the required information by scanning the MemTotal and MemFree fields of /proc/meminfo. Since glibc 2.23, these functions obtain the required information by calling sysinfo(2).

NOTES

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(void) {
    printf("This system has %ld pages of physical memory and "
            "%ld pages of physical memory available.[rs]n",
            get_phys_pages(), get_avphys_pages());
    exit(EXIT_SUCCESS); }