void Halt ();
void Reply (const char * num,uint8_t stat);

{

this is the error message for this code
7|error: 'uint8_t' has not been declared
9|error: expected unqualified-id before '{' token

no idea

uint8_t as others of that ilk are not defined by default by c or c++. You either need to include some header that defines them for you, or you need to define them yourself as in:

typedef unsigned char uint8_t;

As rubberman mentioned, those typedefs are specified in <stdint.h> (for C) and <cstdint> (for C++). But note that <cstdint> wasn't officially supported by C++ until the C++11 standard, so if you're not compiling against that standard then defining your own or using the Boost library would be options to consider.