void fakeBin(const char *digits, char *buffer) { char * digit = digits; char * new_digit = buffer; while (*digit != '\0') { if (*digit >= '5') { *new_digit = '1'; } else { *new_digit = '0'; } digit++; new_digit++; } *new_digit = '\0'; printf("%s\n", digits); printf("%s\n", buffer); }