Is it possible to invoke GHCi from Haskell code? I want to achieve the following effect: have a shell script invoke runhaskell myprog.hs < input.dat and at some point (on conditions) have the prog bring me the ghci prompt GHCi Main> so I can examine my program state interctively, for example place breakpoints, run my functions piecewise? and then do GHCi Main>:continue and then have the prompt again (if conditions) GHCi Main> I did try ghci myprog.hs < input.dat Command-line arguments ghci myprog.hs a b c are similarly by ghci not acceptable In the overall, I want to have the stdin redirected from file once in the GHCi session, place breakpoints and do :step(s) with that stream in this way and cannot also do GHCi Main>:main < input.dat but in my case (I think) this not also an option since its not me but the wrapper script doing the setup. krassi