I have recently found these shell-related libs to be very useful:

"ShQQ, the Shell Quasiquoter": everything is type-safe and passed to the system properly escaped, you don't end up shooting yourself in the foot. This is necessary if you want to do any serious work with such a library. The syntax is very, very easy and clean to read. http://hackage.haskell.org/packages/archive/shqq/0.1/doc/html/System-ShQQ.html

"HSH, the Haskell Shell": http://changelog.complete.org/archives/492-announcing-hsh-the-haskell-shell

"Shelly: Write your shell scripts in Haskell:" http://www.yesodweb.com/blog/2012/03/shelly-for-shell-scripts

You want piping? It's actually part of the Haskell paradigm. Monads? Yup, basically the bind operator is piping. Want super-duper piping? Go with conduits.

"Shell pipes as Monadic IO": http://okmij.org/ftp/Computation/monadic-shell.html

"Conduits are an approach to the streaming data problem": http://hackage.haskell.org/package/conduit

I have tried, but I just can't find any wishes open with this bunch.