table of contents
get_phys_pages(3) | Library Functions Manual | get_phys_pages(3) |
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¶
These functions are GNU extensions.
NOTES¶
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¶
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¶
2022-10-30 | Linux man-pages 6.03 |