GNU C library
From Teknologisk videncenter
Checking which GNU C Library version
To check which GCLIB you are using run this program.
#include <stdio.h>
#include <gnu/libc-version.h>
int main(void) {
printf("GNU C Library version is %s\n", gnu_get_libc_version());
printf("GNU C Library release is %s\n", gnu_get_libc_release());
return 0;
}