File open memory c#
<p>While opening a file in C# using stream reader is the file going to remain in memory till it closed. 
For eg if a file of size 6MB is opened by a program using streamreader to append a single line at the end of the file. Will the program hold the entire 6 MB in it's memory till file is closed. OR is a file pointer returned internally by .Net code and the line is appended at the end. So the 6MB memory will not be taken up by the program</p>
