<div dir="ltr">Yes. As said by Anish, I generally practice through a dummy hello world module. Suppose, if I want to print all the processes currently running, I do like this.<div><br><div><div>#include <linux/module.h></div>
<div>#include <linux/kernel.h></div><div>#include <linux/sched.h></div><div><br></div><div>MODULE_LICENSE("Dual BSD/GPL");</div><div><br></div><div>static int hello_init(void)</div><div>{</div><div><span class="" style="white-space:pre"> </span>struct task_struct *task; </div>
<div><br></div><div><span class="" style="white-space:pre"> </span>printk("Hello World!\n");</div><div><span class="" style="white-space:pre"> </span></div><div><span class="" style="white-space:pre"> </span>for_each_process(task) {</div>
<div><span class="" style="white-space:pre"> </span>printk("%s %d\n", task->comm, task->pid);</div><div><span class="" style="white-space:pre"> </span>}</div><div><span class="" style="white-space:pre"> </span></div>
<div><span class="" style="white-space:pre"> </span>printk("\n\n\n");</div><div><span class="" style="white-space:pre"> </span></div><div><span class="" style="white-space:pre"> </span>for(task = &init_task; ((task=next_task(task)) != &init_task) ; )</div>
<div><span class="" style="white-space:pre"> </span>printk("%s %d\n", task->comm, task->pid);</div><div><span class="" style="white-space:pre"> </span></div><div><span class="" style="white-space:pre"> </span>printk("\n\n\n");</div>
<div><span class="" style="white-space:pre"> </span></div><div><span class="" style="white-space:pre"> </span>return 0;<br></div><div>}</div><div><br></div><div>static void hello_exit(void)</div><div>{</div><div><span class="" style="white-space:pre"> </span>printk("Good bye!\n");</div>
<div>}</div><div><br></div><div>module_init(hello_init);</div><div>module_exit(hello_exit);</div></div><div><br></div></div><div>By the way, you can do as suggested by Valdis, too. I do search for a particular code/strings using find, xargs, grep combination.</div>
<div><br></div><div>I hope this helps you.</div><div><br></div><div>Regards,</div><div>Srinivas</div><div><br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Tue, Jul 16, 2013 at 12:42 PM, Satya Prakash Prasad <span dir="ltr"><<a href="mailto:unixkernel497@gmail.com" target="_blank">unixkernel497@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><span>Thanks .. I have another question. I was trying to practice some kernel process management APIs as in
<a href="http://www.linkedin.com/redirect?url=http%3A%2F%2Freiber%2Eorg%2Fnxt%2Fpub%2FLinux%2FLinuxKernelDevelopment%2FLinux%2EKernel%2EDevelopment%2E3rd%2EEdition%2Epdf&urlhash=3MN8&_t=tracking_disc" target="_blank">http://reiber.org/nxt/pub/Linux/LinuxKernelDevelopment/Linux.Kernel.Development.3rd.Edition.pdf</a>
(Linux Kernel Development by Robert Love, 3rd edition).
<br>
<br>
I am not sure how to practice the code snippet given in the text book. I
can understand the theory but do not find a way to practice. For
example: I want to read a process 'struct task_struct' to find it
parent's process identifier, how many tasks are in which state, creating
kernel threads etc?
<br>
<br>
Any idea?
</span></div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><br><div class="gmail_quote">On Mon, Jul 15, 2013 at 2:32 PM, Srinivas Ganji <span dir="ltr"><<a href="mailto:srinivasganji.kernel@gmail.com" target="_blank">srinivasganji.kernel@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div>As per as I know, you can follow two text books. <br></div><div><br></div><div>1. Linux Kernel Development by Robert Love, 3rd edition. </div>
<div>2. Linux Device Drivers by Alessandro Rubini, Jonathan Corbet, Greh Kroah-Hartman. 3rd edition.</div>
<div><br></div><div>At the same time, you can practice the exercises given in the text books - practice makes a man perfect. The other thing is "Make your hands dirty by digging the kernel code whenever you have a doubt".</div>
<div><br></div><div>Regards,</div><div>Srinivas</div><div><br></div><div><br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote"><div><div>On Mon, Jul 15, 2013 at 2:06 PM, Satya Prakash Prasad <span dir="ltr"><<a href="mailto:unixkernel497@gmail.com" target="_blank">unixkernel497@gmail.com</a>></span> wrote:<br>
</div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div><div dir="ltr"><div>Please let me know how to study and get hands on experience on Linux Kernel and Device Drivers?<br>
<br></div>Regards,<br>Prakash<br></div>
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