what is eof char in c#

Question

Hi, I am facing a weird issue. Here it goes: I am writing a c# app for a client with which I will read some data and generate a .dat file for them from that data. Then the client will read that .dat file and do something based on it's contents at their end. My application will run on a windows xp machine but client should be able to read this dat file in unix box. So, they want to know what will be the end of line character (which I said will be standard \r\n), but they also insist on knowing what is enf of file character. Now, I have read that there is no specal EOF character in c#, so what should I tell my client. They said they need to know all this as they will be reading this dat file on a unix box. Please enlighten me. Thanks dev_kh