Re: [PARPORT] Can I...

Tim Waugh (
Thu, 22 Oct 1998 09:36:54 +0100 (BST)

On Thu, 22 Oct 1998, Keith Baker wrote:

> I have a small Parallel port -> DMX (A stage lighting protocol)
> converter. I would like to write software for it under linux. I need
> to be able to read and write to the || port pins... I think the paper
> out pin for example. I guess if I understand correctly root could do
> this with a simple write to that io address... But I want to be able
> to run it as an ordinary user... How would I go about it?

If you want to have your executable running as non-root (rather than just
runnable as non-root, i.e. setuid), then you might want to look at
"ppuser" <>.

It provides a sort of /dev/parport, which could have access writes
allowing users to mess with the parallel port.

The way you use it is that you open() the device node, and use some ioctls
to claim the port and write the registers.

There is an example program to drive a printer included in the tarball.


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This archive was generated by hypermail 2.0b3 on Wed 30 Dec 1998 - 10:18:39 EST