Manpages - get_phys_pages.3

get_phys_pages, get_avphys_pages - get total and available physical page counts

  #include <sys/sysinfo.h>

  long get_phys_pages(void);
  long 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.

On success, these functions return a nonnegative value as given in DESCRIPTION. On failure, they return -1 and set errno to indicate the error.

ENOSYS

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

These functions are GNU extensions.

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).

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>

  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);
  }

*sysconf*(3)

This page is part of release 5.13 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/.