The question is descriptive, but further details:
what are the steps in developping a light software that can show all the pdf files on my hard drive and tell me which one are corrupted, can fix pdf (if this is possible), and ask me if i want to put a pdf in a particular folder?
my challenge is to use elegant code:) I need a starter to begin the work.
This process is generally called preflighting, or preflight checking. The steps include:
1) Finding PDF files This is quite easily done programmatically, I would assume that one would copy these to a location for the preflight checks.
2) A corrupt PDF could mean a number of things depending on what you want to do wit the PDF, for instance if you're checking a PDF for printing, you would need to check colour, fonts, existance of non-support media etc. Interpretting PDF files is not a trivial task, you can use GhostScript, ITextSharp (open source) or commercial PDF libraries from Tall Components etc to performs various tests.
For a definitive result, and ability to fix files you should have a look at commercial preflighting tools, Have a look at the products from Marksware and OneVision.