POS USB raw data sniffer

I need an app to run on the Raspberry Pi (Linux) which can achieve the following; 1 - POS Computer connected to Raspberry Pi (via USB) 2 - Raspberry Pi connected to a POS Printer (via USB) 3 - When POS prints docket Raspberry Pi sniffers the RAW stream and sends to a database 4 - RAW stream is passed on to POS printer The goal is to 1) capture the exact data passed from the POS to the Printer and 2) do not interfere with the printing process We need this data so that we can store digital receipts from our POS. If you think you can develop this app then make a bid! Thanks for looking.