End Google Ads 201810 - BS.net 01 --> My task is as follows...

I have 2 data files a Source (A) and a Destination (B) both located in the shared network drive.
A is a data file (plain text) between 2GB and 3GB made up of records of fixed size.
A is always being written into by other processes (new records being appended at the end).

I would like to read through the whole file A, read each record, leave what I still need and archive the rest to B.
There is a 10 character string I can use within each record as a filter.

My question is, is there a (fast, as in run-time fast) way to do this in C#? I have been trying to do this with MMF but I'm beginning to think it's overkill?

Thanks for any help.

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