#include <sys/types.h> int main(int argc, char **argv) { /* Cause a compile-time error if off_t is smaller than 64 bits */ #define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62)) int off_t_is_large[ (LARGE_OFF_T % 2147483629 == 721 && LARGE_OFF_T % 2147483647 == 1) ? 1 : -1 ]; return 0; }