req for code

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