#include #include #include #include #include #include //limits> using namespace std; int sof = sizeof(float); // Should use language vars. int soi = sizeof(int); int sod = sizeof(double); // ------------------------------------------------------ // Get access to internal bytes of data larger types // ------------------------------------------------------ union float_bytes { float val; unsigned char bytes[sizeof(float)]; // exact overlay of float } fData; union int_bytes { int val; unsigned char bytes[sizeof(int)]; // exact overlay of int } iData; union double_bytes { double val; unsigned char bytes[sizeof(double)]; } dData; char guard=255; // ------------------------------------------------------ void dShowHex(double* dp, char guard) { cout << "0x"; dData.val = *dp; for (int i=0; i < sod; i++) { printf("%02X ", dData.bytes[sod-i-1]); // Human output... } } void fShowHex(float* fp) { cout << "0x"; fData.val = *fp; for (int i=0; i < sof; i++) { printf("%02X ", fData.bytes[sof-i-1]); // Human output... } } void iShowHex(int* intp) { cout << "0x"; iData.val = *intp; for (int i=0; i < soi; i++) { printf("%02X ", iData.bytes[soi-i-1]); /* ...largest byte (left) * is highest byte of * memory in little- * endian systems. * Values are stored UP * the heap; you have to * address in REVERSE. */ } } int main() { // Show internal FLOAT structure // -------------------------------------- float* fp = (float *)malloc(sof); if(fp) { *fp=1024.0f; fShowHex(fp); printf("<-Float: %f\n", *fp); free(fp); } else { cout << "Problem allocating float." < way%c.\n", iData.val, char(166)); cout << "\nThe memory heap is said to grow 'up' (low->high). It's copy-efficient (forward through vars is always increasing), ex:" << endl; printf("\n char(2049)==?...%d\n\n", char(2049)); cout << char(166)<<" Historically, NETWORK protocol byte order is BIG-endian."; return 0; }

floats/doubles/ints