Re: [Caml-list] Unix.create_process vs Unix.open_process_out

[Gerd Stolpmann <info@gerd-stolpmann.de>]

Am Montag, den 14.04.2008, 08:43 -0400 schrieb James Jones:
> Consider the following two functions:
> 
> let test1 () =
>   let w = Unix.open_process_out "cat" in
>   assert (Unix.close_process_out w = Unix.WEXITED 0)
> 
> let test2 () =
>   let r,w = Unix.pipe () in
>   let pid = Unix.create_process "cat" [| "cat" |] r Unix.stdout
> Unix.stderr in
>   Unix.close w;
>   assert (snd (Unix.waitpid [] pid) = Unix.WEXITED 0)

P.S. You can close the "other" w by setting the close on exec flag:

let test2 () =
  let r,w = Unix.pipe() in
  Unix.set_close_on_exec w;
  let pid = Unix.create_process "cat" [| "cat" |] r Unix.stdout
Unix.stderr in
  Unix.close w;
  assert (snd (Unix.waitpid [] pid) = Unix.WEXITED 0);;

Gerd


> 
> 
> Both execute "cat" and then close its stdin immediately. This should
> cause cat to terminate. In test1 this works as expected but in test2,
> cat keeps running forever. Is this the expected behavior of
> Unix.create_process? 
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