get_phys_pages(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | NOTES | EXAMPLES | SEE ALSO | COLOPHON

GET_PHYS_PAGES(3)       Linux Programmer's Manual      GET_PHYS_PAGES(3)

NAME         top

       get_phys_pages, get_avphys_pages - get total and available
       physical page counts

SYNOPSIS         top

       #include <sys/sysinfo.h>

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

DESCRIPTION         top

       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         top

       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         top

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

CONFORMING TO         top

       These functions are GNU extensions.

NOTES         top

       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 */

EXAMPLES         top

       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);
       }

SEE ALSO         top

       sysconf(3)

COLOPHON         top

       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/.

GNU                            2021-03-22              GET_PHYS_PAGES(3)

Pages that refer to this page: undocumented(3)