What you can do is return the data from the lazy read strictly, and the close the file handle. using the Strategies library you get something like: a <- hGetContents h b <- return $ processInput a rnf a `seq` hClose h Sometimes even this does not appear to be strict enough (in my experiance when processInput includes operations like map, then you have to "rnf" the data before the map as well. Sometimes I end up passing the file handle with the stream, to enable me to close it as soon as possible. Regards, Keean Schupke. -----Original Message----- From: glasgow-haskell-users-admin@haskell.org [mailto:glasgow-haskell-users-admin@haskell.org]On Behalf Of Hal Daume III Sent: 11 April 2003 20:11 To: GHC Users Mailing List Subject: Posix.createPipe failing After running a few hundred createPipe's, they begin to fail for me, giving the error: Fail: system error Action: createPipe This seems to me to be like the "not enough file handles" error you get when using lazy readFile, since this doesn't close the handle soon enough. Am I correct in this intuition and if I am (or otherwise), how do I fix it? Thanks! - Hal -- Hal Daume III | hdaume@isi.edu "Arrest this man, he talks in maths." | www.isi.edu/~hdaume _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users