Hello!
A few months ago, I started a discussion about how to extract the file
descriptor of a handle, without the side effect of closing the handle. Bas van
Dijk kindly provided the following function:
unsafeWithHandleFd :: Handle -> (Fd -> IO a) -> IO a
(The action in the second argument is a
Hi
This is an addition to my previous post.
This modified version of main seems to work:
main = do
fd <- unsafeWithHandleFd stdin return
putStrLn ("stdin: fd = " ++ show fd)
fd <- unsafeWithHandleFd stdout return
putStrLn ("stdout: fd = " ++ show fd)
The way I understand it,
Can you use 'dup' to copy the file descriptor and return that version?
That will keep a reference to the file even if haskell closes the
original descriptor.
John
On Sat, Mar 10, 2012 at 5:31 PM, Volker Wysk wrote:
> Hi
>
> This is an addition to my previous post.
>
>
> This modified versio
On 11/03/2012 01:31, Volker Wysk wrote:
Hi
This is an addition to my previous post.
This modified version of main seems to work:
main = do
fd<- unsafeWithHandleFd stdin return
putStrLn ("stdin: fd = " ++ show fd)
fd<- unsafeWithHandleFd stdout return
putStrLn ("stdout: fd =
Am Montag 12 März 2012, 12:31:27 schrieb Simon Marlow:
> On 11/03/2012 01:31, Volker Wysk wrote:
> > However, I want to use it with stdin, stdout and stderr, only.
>
> Is there some reason you can't just use 0, 1, and 2?
This is complicated. I want to be able to fork a child action, and communica
