Help on handles

[Yeo Gek Hui]

Hi,
Has anyone have experience reading from a handle using hGetContents when
the handle is still open and receives input from outside?
I need to do some manipulation to the contents and I can't afford to close
this handle. for example, an infinite stream "abcabc..." is written from
outside to this handle and I know that 'c' means the termination and I
want to get "abc", "abc" and the rest coming. I have used no-buffering for
my handle and have written a function,extractC to extract the string end  
with the terminating character c. There is one more function, keepRest
to keep the remainder of the stream. However, let's say response <-
hGetContents handle and the response still has "abcabc...". I know in
imperative language, response can be reassigned globally. How can I do
that in Haskell? This is because I want to avoid duplications and ensure
the program terminates.
Thanks a lot.
Cheers,
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