[Haskell-cafe] Re: GHC throws IOError on Win32 when there is no console

Simon Marlow simonmarhaskell at gmail.com
Tue Feb 13 07:59:59 EST 2007

Krasimir Angelov wrote:
> On 2/13/07, Simon Marlow <simonmarhaskell at gmail.com> wrote:
>> Sounds like a good idea.  You need to look at rts/RtsMessages.c, in 
>> particular
>> rtsErrorMsgFn(), which currently has cases for GUI and non-GUI.  I 
>> guess it
>> really should have 3 cases: GUI, console, and non-GUI.
> The trick here is how to find whether the current application is GUI,
> console or non-GUI. The distinction between GUI and Console
> applications is easy because you can check subsystem OS type. This
> doesn't work with Windows services because they can be either GUI or
> Console. The OS is preventing them from showing any windows.

So then a program which is running as a service should explicitly set a 
different message handler.  Maybe we could provide a handler that sends messages 
to the system log.


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