cannot open null: for I/O redirection

John Tytgat John.Tytgat at aaug.net
Sun Oct 12 14:28:18 PDT 2003


In message <4c3f54c42asbellon at sbellon.de>
          Stefan Bellon <sbellon at sbellon.de> wrote:

> I found something strange in UnixLib. When using
> __RISCOSIFY_NO_PROCESS, then I'd expect the program linked against
> UnixLib to handle native RISC OS file names.
> 
> If I do:
> 
> *myapp > null:
> 
> it works. However, if I do:
> 
> *myapp < null:
> 
> then I get "cannot open null: for I/O redirection". If I however do:
> 
> *myapp < /dev/null
> 
> then that works again. But I'd expect "null:" to work.
> 
> What's puzzling me is the fact that "null:" as stdout works but not as
> stdin.

The reason is that the "null:" gets handled by __fsopen() (the standard
RISC OS open() implementation) and that's not 100% suited for real
/dev/null behaviour.  We do however have a proper /dev/null open()
implementation (i.e. __nullopen()) and this routine gets now selected
by the patch I've just commited in CVS.

Jo.
-- 
John Tytgat, in his comfy chair at home                                 BASS
John.Tytgat at aaug.net                             ARM powered, RISC OS driven




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