Quoth Jason Dusek
Using `System.Process.runInteractiveProcess', I can start a process and get a handle to it:
runInteractiveProcess :: FilePath -> [String] -> Maybe FilePath -> Maybe [(String, String)] -> IO (Handle, Handle, Handle, ProcessHandle)
For diagnostic purposes, I'd like to print the PID of the process attached to this handle -- how best to do that?
There's a good chance this isn't the best way, but it seems to work: import System.Process import System.Process.Internals (ProcessHandle__(..), PHANDLE, withProcessHandle) -- for use with withProcessHandle getPID :: ProcessHandle__ -> IO (ProcessHandle__, Maybe PHANDLE) getPID h@(OpenHandle t) = return (h, Just t) getPID h@(ClosedHandle t) = return (h, Nothing) main = do (h0, h1, h2, hp) <- runInteractiveProcess "/bin/date" [] Nothing Nothing mp <- withProcessHandle hp $ getPID print mp Seems like more scaffolding than this application really ought to require. Donn