uinput on headless system ...

uinput on headless system ...

[Roberto Alejandro Espi Munoz]

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.

Any thoughts on this? or can you redirect me to an ongoing mailing list 
about the kernel input system

Thanks in advance ...

Re: uinput on headless system ...

[Dmitry Torokhov]

Hi Roberto,

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

Thanks.

-- 
Dmitry

Re: uinput on headless system ...

[Benjamin Tissoires]

Hi Roberto,

On Wed, Jan 13, 2016 at 11:21 PM, Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:
> Hi Roberto,
>
> On Wed, Jan 13, 2016 at 09:19:39AM -0500, Roberto Alejandro Espi Munoz wrote:
>> 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/

Re: uinput on headless system ...

[Roberto Alejandro Espi Munoz]

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
> <dmitry.torokhov@gmail.com> wrote:
>> Hi Roberto,
>>
>> On Wed, Jan 13, 2016 at 09:19:39AM -0500, Roberto Alejandro Espi Munoz wrote:
>>> 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/
> --
> To unsubscribe from this list: send the line "unsubscribe linux-input" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: uinput on headless system ...

[Benjamin Tissoires]

On Thu, Jan 14, 2016 at 3:05 PM, Roberto Alejandro Espi Munoz
<raespi@icid.cu> wrote:
> 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;
>

Just to be sure, is there any sleep here or way to ensure your
motherboard actually opened the device here?
If not, you might simply send the events too early, when nobody reads
them, and thus you think you did not receive them.

Cheers,
Benjamin

>     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
>> <dmitry.torokhov@gmail.com> wrote:
>>>
>>> Hi Roberto,
>>>
>>> On Wed, Jan 13, 2016 at 09:19:39AM -0500, Roberto Alejandro Espi Munoz
>>> wrote:
>>>>
>>>> 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/
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-input" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
>
>

Re: uinput on headless system ...

[Roberto Alejandro Espi Munoz]

Well yes ... the code I posted is actually part of a TCP server client 
connection.  One part of the code gets executed up to the point you 
mentioned.  The part where the keys get sent only executes when 
receiving the network command, so yes, there is a time lapse between one 
part and the other.

On 01/14/2016 09:27 AM, Benjamin Tissoires wrote:
> On Thu, Jan 14, 2016 at 3:05 PM, Roberto Alejandro Espi Munoz
> <raespi@icid.cu> wrote:
>> 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;
>>
> Just to be sure, is there any sleep here or way to ensure your
> motherboard actually opened the device here?
> If not, you might simply send the events too early, when nobody reads
> them, and thus you think you did not receive them.
>
> Cheers,
> Benjamin
>
>>      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
>>> <dmitry.torokhov@gmail.com> wrote:
>>>> Hi Roberto,
>>>>
>>>> On Wed, Jan 13, 2016 at 09:19:39AM -0500, Roberto Alejandro Espi Munoz
>>>> wrote:
>>>>> 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/
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-input" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-input" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: uinput on headless system ...

[Roberto Alejandro Espi Munoz]

Bump ... any other insights or suggestions I could try?

On 01/14/2016 10:16 AM, Roberto Alejandro Espi Munoz wrote:
> Well yes ... the code I posted is actually part of a TCP server client 
> connection.  One part of the code gets executed up to the point you 
> mentioned.  The part where the keys get sent only executes when 
> receiving the network command, so yes, there is a time lapse between 
> one part and the other.
>
> On 01/14/2016 09:27 AM, Benjamin Tissoires wrote:
>> On Thu, Jan 14, 2016 at 3:05 PM, Roberto Alejandro Espi Munoz
>> <raespi@icid.cu> wrote:
>>> 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;
>>>
>> Just to be sure, is there any sleep here or way to ensure your
>> motherboard actually opened the device here?
>> If not, you might simply send the events too early, when nobody reads
>> them, and thus you think you did not receive them.
>>
>> Cheers,
>> Benjamin
>>
>>>      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
>>>> <dmitry.torokhov@gmail.com> wrote:
>>>>> Hi Roberto,
>>>>>
>>>>> On Wed, Jan 13, 2016 at 09:19:39AM -0500, Roberto Alejandro Espi 
>>>>> Munoz
>>>>> wrote:
>>>>>> 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/
>>>> -- 
>>>> To unsubscribe from this list: send the line "unsubscribe 
>>>> linux-input" in
>>>> the body of a message to majordomo@vger.kernel.org
>>>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>>>
>>>
>> -- 
>> To unsubscribe from this list: send the line "unsubscribe 
>> linux-input" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
>
> -- 
> To unsubscribe from this list: send the line "unsubscribe linux-input" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: uinput on headless system ...

[Dmitry Torokhov]

On Tue, Jan 19, 2016 at 09:55:00AM -0500, Roberto Alejandro Espi Munoz wrote:
> Bump ... any other insights or suggestions I could try?
> 

You can check what error you are getting when trying to open the device
and that might give you idea.

Thanks.

-- 
Dmitry

Re: uinput on headless system ...

[Roberto Alejandro Espi Munoz]

The error is produced when the write operation doesn't return the same 
number of bytes as the one requested to write.  Is there any other way 
of checking a specific error message on files associated with devices?

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

On 01/19/2016 04:36 PM, Dmitry Torokhov wrote:
> On Tue, Jan 19, 2016 at 09:55:00AM -0500, Roberto Alejandro Espi Munoz wrote:
>> Bump ... any other insights or suggestions I could try?
>>
> You can check what error you are getting when trying to open the device
> and that might give you idea.
>
> Thanks.
>

Re: uinput on headless system ...

[Dmitry Torokhov]

On Tue, Jan 19, 2016 at 1:58 PM, Roberto Alejandro Espi Munoz
<raespi@icid.cu> wrote:
> The error is produced when the write operation doesn't return the same
> number of bytes as the one requested to write.  Is there any other way of
> checking a specific error message on files associated with devices?
>
> if (write( uinputDev, &event, sizeof(struct input_event)) != sizeof( struct
> input_event) )
> {
>     fprintf(stderr, "Error on send_event");
>     return -1;
>  }

1. Could you please stop top-posting
2. man errno; man strerror
3. I wonder what was the return value from write() and what is
sizeof(struct inptu_event) on your system.
4. Please do take care when describing your problem. In your original
email you said that "... the uinput device fails to open".
5. Is it system with 64 bit kernel and 32 bit userspace by any chance?

Thanks.

 >
> On 01/19/2016 04:36 PM, Dmitry Torokhov wrote:
>>
>> On Tue, Jan 19, 2016 at 09:55:00AM -0500, Roberto Alejandro Espi Munoz
>> wrote:
>>>
>>> Bump ... any other insights or suggestions I could try?
>>>
>> You can check what error you are getting when trying to open the device
>> and that might give you idea.
>>
>> Thanks.
>>
>
>

-- 
Dmitry