req for code

[Benedict Kavanagh]

Writing some system code. Want to do it in Haskell. As a head start 
boost does anybody have any code that

uses forkprocess to fork, creates a pipe between parent/child and dups 
child's end to be standard out for the child  and then  have the parent  
do something based on something the child says. 

I'll just go ahead and write it but I was wondering how integrated IO() 
stuff is with low level file calls. An example would help.

Anyone got any code that I could look at? Is there any code in any 
library or other code that does this kind of stuff?

google turned up zilch.

Thanks
Ben