Re: [PARPORT] Timeout on write

From: Tim Waugh (
Date: Wed Oct 10 2001 - 13:33:31 EDT

  • Next message: Sam Spade: "Re: [PARPORT] Problem with 2 paralell ports"

    On Wed, Oct 10, 2001 at 11:05:25AM -0600, Brad Pepers wrote:

    > With the latest Linux kernels (using 2.4.10 right now), I can't seem to find
    > a way to make a write fail if there is no parallel port device. For example
    > I have a Epson TM-T88 printer on the parallel port and I send a status
    > request to it every few seconds. If the printer gets turned off I want the
    > write to just fail immediately. In the past I could use "tunelp -a on" to
    > get this behaviour but it doesn't seem to work anymore.
    > Anything I can do to help get this working again?

    'tunelp -a on' ought to still work. I am quite busy with other things
    still at the moment and so don't have time to look at it just now. Do
    you think you could take a look to see how lp_open is handling the
    ABORT flag differently?

    > PS: once I get past this problem with writes, I will need to see if I can
    > also make sure reads work properly. What I need is non-blocking behaviour.
    > I will request a read for a few bytes but if there aren't enough available
    > (or none), I want it to just return back that it read 0 is how ever many
    > bytes were available. Does the printer driver handle the non-blocked flag
    > properly?

    No, but it shouldn't be hard for someone (who has the hardware to test
    it with) to fix that.


    -- To unsubscribe, send mail to: --
    -- with the single word "unsubscribe" in the body of the message. --

    This archive was generated by hypermail 2b29 : Wed Oct 10 2001 - 13:35:14 EDT