ghci's :def takes a 'String -> IO String' and converts it into a ghci command. this makes it possible to pass a command parameter to a haskell function, and to interpret the result of the call as a ghci command. that is nice, but how do i get access to the command's output? that is, i'd like to run a ghci command, and capture its ouput as a haskell String, eg, to pass it on to another ghci command, or to a haskell function. perhaps something simple, like an additional ghci top-level binding: GHCi.cmd :: String -> IO String so that i could write things like let doSomething output = .. :def mymodules \_->GHCi.cmd ":show modules" >>= doSomething or a way to compose ghci commands, so that i could write :def doSomething \output->.. :def mymodules \_->return ":show modules :>>= :doSomething" would that be difficult to provide? claus