get_phys_pages(3) — Linux manual page

get_phys_pages(3)        Library Functions Manual       get_phys_pages(3)

NAME         top

       get_phys_pages, get_avphys_pages - get total and available
       physical page counts

LIBRARY         top

       Standard C library (libc, -lc)

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).

STANDARDS         top

       GNU.

HISTORY         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).

NOTES         top

       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(void)
       {
           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

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Linux man-pages 6.15            2025-05-17              get_phys_pages(3)

Pages that refer to this page: undocumented(3)

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