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