#include int is_big_endian(void) { uint32_t one = 1; if(*((uint8_t*) &one) == 1) return 0; return 1; } int main() { int is_be_check = is_big_endian(); int is_be; #ifdef IS_BE is_be = 1; #else is_be = 0; #endif if(is_be_check && is_be) return 0; if(!is_be_check && !is_be) return 0; return 1; }