Quoth "Serge D. Mechveliani"
Initially, I did the example by the Foreign Function Interface for C. But then, I thought "But this is unnatural! Use plainly the standard Haskell IO, it has everything".
So, your advice is "return to FFI" ?
Well, it turns out that the I/O system functions in System.Posix.IO may work for your purposes. I was able to get your example to work with these functions, which correspond to open(2), read(2), write(2). I would also use these functions in C, as you did in your C program. Haskell I/O functions like hGetLine are analogous to C library I/O like fgets(3) - in particular, they're buffered, and I would guess that's why they don't work for you here. Specifically, openFile "toA" WriteOnly Nothing defaultFileFlags openFile "fromA" ReadOnly Nothing defaultFileFlags fdWrite toA str (str, len) <- fdRead fromA 64 return str Donn