Re: uinput on headless system ...

Yes the uinput driver is compiled as a module and loaded before running the test app that I have (double checked with modprobe and lsmod).  The same code has been compiled for my laptop and everything loads and works fine when sending events to the input subsystem.   I mentioned the physical keyboard issue because that's what made it work: SCENARIO1 the headless motherboard starts without a keyboard and both the module and the app loads but no events get injected and the problem occurs when writing to the /dev/uinput device, SCENARIO2 I connect a physical keyboard and all goes well. I looked at the libevdev before and sinced my code ended up working on my laptop I discarded the library.  I saw the libevdev-uinput.c you recommended, I think I'm following the same rationale.

Thanks for the replies ...

This is the code I'm using that fails at the end when writing to the /dev/uinput device:

    int uinputDev;
    struct uinput_user_dev device;
    memset(&device, 0, sizeof device);

    uinputDev = open("/dev/uinput",O_WRONLY | O_NONBLOCK);
        strcpy(device.name,"test remote");

        device.id.bustype=BUS_USB;
        device.id.vendor=1;
        device.id.product=1;
        device.id.version=1;


        if (write(uinputDev,&device,sizeof(device)) != sizeof(device))
        {
            fprintf(stderr, "error setup\n");
        }
        if (ioctl(uinputDev,UI_SET_EVBIT,EV_KEY) < 0)
            fprintf(stderr, "error evbit key\n");

        if (ioctl(uinputDev,UI_SET_KEYBIT, KEY_LEFT) < 0)
            fprintf(stderr, "error evbit key\n");

        if (ioctl(uinputDev,UI_SET_KEYBIT, KEY_UP) < 0)
            fprintf(stderr, "error evbit key\n");

        if (ioctl(uinputDev,UI_SET_KEYBIT, KEY_DOWN) < 0)
            fprintf(stderr, "error evbit key\n");

        if (ioctl(uinputDev,UI_SET_KEYBIT, KEY_RIGHT) < 0)
            fprintf(stderr, "error evbit key\n");

        if (ioctl(uinputDev,UI_SET_KEYBIT, KEY_ENTER) < 0)
            fprintf(stderr, "error evbit key\n");

        if (ioctl(uinputDev,UI_DEV_CREATE) < 0)
        {
            fprintf(stderr, "error create\n");
        }

     struct input_event event;

    memset(&event, 0, sizeof(event));
    event.type = EV_KEY;
    event.code = KEY_UP;
    event.value = 1;
    gettimeofday(&event.time,NULL);

    if (write( uinputDev, &event, sizeof(struct input_event)) != sizeof( struct input_event) ) {
        fprintf(stderr, "Error on send_event");
        return -1;
    }

    memset(&event, 0, sizeof(event));
    event.type = EV_KEY;
    event.code = KEY_UP;
    event.value = 0;
    gettimeofday(&event.time,NULL);

    if (write( uinputDev, &event, sizeof(struct input_event)) != sizeof( struct input_event) ) {
        fprintf(stderr, "Error on send_event");
        return -1;
    }

On 01/14/2016 12:08 AM, Benjamin Tissoires wrote:

Hi Roberto,

On Wed, Jan 13, 2016 at 11:21 PM, Dmitry Torokhov
[off-list ref] wrote:

quoted

Hi Roberto,

On Wed, Jan 13, 2016 at 09:19:39AM -0500, Roberto Alejandro Espi Munoz wrote:

quoted

Hello ... I've been searching around the web for a specific mailing
list for the uinput driver but couldn't find any.  I managed to
create an example app that injects keyboard events to the running
linux kernel succesfully when I have a keyboard attached to the
computer.  However if I run it on a keyboardless machine, like a
standalone motherboard, the uinput device fails to open.

uinput driver does not depend on presence of a physical keyboard. I'd
start looking whether uinput module is enabled on your headless box and
if it is a module verify that it is loaded.

As Dmitry said, uinput is independent of any attached hardware.
You might want to see how we managed to create new devices through
uinput by looking at libevdev[1] (see libevdev/libevdev-uinput.c).

You might actually also want to use libevdev instead of manually doing
the ioctls and processing of all the small things :)

Cheers,
Benjamin

[1] http://www.freedesktop.org/wiki/Software/libevdev/
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