The OutputDebugString function sends a string to the debugger for the current application.
VOID OutputDebugString(
  LPCTSTR lpOutputString   // pointer to string to be displayed
);
 
This function does not return a value.
If the application has no debugger, the system debugger displays the string. If the application has no debugger and the system debugger is not active, OutputDebugString does nothing.
Windows CE: Windows CE supports only the Unicode version of this function.
  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Requires version 1.0 or later.
  Header: Declared in winbase.h.
  Import Library: Use kernel32.lib.
  Unicode: Implemented as Unicode and ANSI versions on Windows NT.
Debugging Overview, Debugging Functions