<br><br><div class="gmail_quote">On Tue, Jul 5, 2011 at 9:15 AM, Bond <span dir="ltr"><<a href="mailto:jamesbond.2k.g@gmail.com">jamesbond.2k.g@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
This is an interview question.<br>
<br>
I had written device driver for a char device so I know that code<br>
structure looks like this<br>
<br>
struct file_operations something {<br>
.owner=my_device_open;<br>
.read=my_device_read;<br>
.close=my_device_close;<br>
.write=my_device_write;<br>
<br>
}<br>
When the device driver is active then in<br>
<br>
/dev/mydevice<br>
you can actually read and write into it. But what I was not clear is<br>
how an application will read or write to this device. I know insmod<br>
will insert the module to kernel,and register_chrdev(); will register<br>
the driver in kernel but how will application program communicate with<br>
this driver.<br>
<br>
<br>
My answer was<br>
In unix it simply opens the device node as a file and sends/receives<br>
data and commands from it.<br>
<br>
But he was expecting some thing more complex.<br>
<br>
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</blockquote></div><br>Hi,<br><br>Not in touch with low level stuff for some time but do check ioctl() and sysfs on wikipedia or man pages.<br><br>Take care.<br clear="all"><br>-- <br>Shahbaz Khan<br>R&D Engineer,<br>
Tactical Engineering and Consultancy.<br><br><a href="http://shazkhan.wordpress.com/" target="_blank">http://shazkhan.wordpress.com/</a><br><a href="http://pk.linkedin.com/pub/shahbaz-khan/20/116/b49" target="_blank">http://pk.linkedin.com/pub/shahbaz-khan/20/116/b49</a><br>
<a href="http://imsciences.edu.pk/serg/" target="_blank">http://imsciences.edu.pk/serg/</a><br><a href="http://csrdu.org/" target="_blank">http://csrdu.org/</a><br>+92-91-332-9915828<br><br>