[fpc-pascal] Interfacing with the free pascal compiler ?

[Skybuck Flying]

Hello,

Is there a special way to interface with the free pascal compiler, for 
example via a DLL/API ?

Or is an IDE supposed to interface via the FPC executable, command line 
parameters, and input files and console output with possibly output 
re-direction to files or so ?

For example, I build a small IDE and now I would like to do something for 
example:

1. Get a list of files tried by the compiler so I don't have to compile 
those again.

2. Get a list of error messages, possibly per tried file, or simply one big 
file for chronological programming mistakes.

Bye,
  Skybuck.