Capture data from Receipt Printer (OPOS & Windows)

We need a program/process developed which should silently be able to capture all the plain text (excluding any images) from any print job that is being sent for printing to any of the multiple printers installed on the system (even if the printer is a shared one on a Local network OR a generic/text printer OR OPOS printer). The data should be written into a text file and saved at the provided location. The Data should be printed to the printer without any loss of data and format. The captured text file should be in the exact same format as it would be printed. The process should be completely silent. It needs to be developed preferably in C# .NET framework 2.0 or above, should work both on Windows & Linux This is part of a project to integrate multiple point of sale systems running in an organization. The documents whose data is to captured would be primarily customer receipts and agent coupons. The process needs to be silent in order not to interfere with the business processes of the organization. The integration of the data from multiple POS must be done as seamlessly as possible. Please note: The default setting of a printer is to use the spool but there is also a sending Print directly to the printer. Process should be able to capture text in case of both, spool and direct printing! It should be able to capture text from the print job irrespective of how and from which source the print has been sent.