Other possibilities:
1) You have two files and the main() function is referring to functions defined in the other file. So, you should define a header file for the other file that shows the profile of the functions. And in the file having the main function, you would include a header like this:
#include "somefilename.h"
In somefilename.h you should have something like the following:
#ifndef SOMEFILENAME_H
#define SOMEFILENAME_H
// provide the declarations of all the functions defined in your somefilename.cpp file
// for example:
int checkPass( char * Pbuffer);
. . .
#endif
2) Potential Build Issues:
If Linux environment, you need to compile both files and use both names when creating the executable. This can be done in one step: g++ file1.cpp file2.cpp and your result will be an executable (e.g., a.exe).
If Visual Studio (or other Windows IDE), make sure that both files are in the project; I would put both files in the same folder, and include your own header file in the same folder as well.
