I/O operations - open, modify and save

what's the easiest way of opening a file f开发者_StackOverflow社区rom disk, modify it (adding a blank space) and then save it again?

thanks

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Take a look at these posts:

http://www.geekpedia.com/tutorial109_File-operations-IorO.html

http://www.csharp-station.com/HowTo/ReadWriteTextFile.aspx

http://www.csharphelp.com/2005/12/simple-text-file-operations-in-c/