On Monday 14 January 2002 19:57, you wrote:
> On Mon, Jan 14, 2002 at 07:03:17PM +0000, Tom Bird wrote:
> > On Mon, 14 Jan 2002, Graeme Fowler wrote:
>> This is probably ugly, evil and just totally wrong, but when I needed to
>> send data to the serial port to control the little LCD screen thing I
>> acquired, I just used /dev/ttyS0 like a file and shoved the data into
>> that.
> I can't see why that's necessarily so wrong - all communication is
> via 'files' in *nix so why should doing that be so wrong?
I think that's beautiful and good orthogonal behavious.
Not at all, it's using ioctl's that is ugly. The I/O absolutely has to go
through a device, which is generally accessed via a filedescriptor, openened
on some filename. Even the tty (and many programs open /dev/tty for terminal
i/o) for standard output has to be opened by something, either getty or login
though the detail's not important.
There was quite alot of discussion on LMKL a while back about using Plan 9
style filenames to set IOCTL's from user space on drivers. Soemthing like
/dev/ttyS1/speed=19200 for example. Or should you echo speed=19200 >
/proc/sys/ttyS1?
Rob
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