Redirecting output

Redirecting output

[shafa.hidee]

Hi,
     I have created a dummy module for learning device driver in linux. I
want to redirect the standard output of printk to my xterm. But by default
it is redirected to tty.

I have remote logged into the machine.

Please help.

Regards
Shafa.hidee

Re: Redirecting output

[Jan Engelhardt]

>Hi,
>     I have created a dummy module for learning device driver in linux. I
>want to redirect the standard output of printk to my xterm. But by default
>it is redirected to tty.

What shall happen if you close the pts of the xterm?



Jan Engelhardt
-- 

Re: Redirecting output

[Martin Waitz]

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hoi :)

On Wed, Mar 23, 2005 at 12:12:02PM +0530, shafa.hidee wrote:
>      I have created a dummy module for learning device driver in linux. I
> want to redirect the standard output of printk to my xterm. But by default
> it is redirected to tty.

The kernel does not have 'standard output', so you can't redirect it.
Please consult the manual for dmesg and syslog.

And please have a look at a good Linux kernel book.
This will help you understand the kernel and will answer most
of your questions.

-- 
Martin Waitz

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Re: Redirecting output

[Andrew Morton]

"shafa.hidee" <shafa.hidee@gmail.com> wrote:
>
>      I have created a dummy module for learning device driver in linux. I
>  want to redirect the standard output of printk to my xterm. But by default
>  it is redirected to tty.
> 
>  I have remote logged into the machine.

You can do this from within the module_init() handler only:

module_init_handler(...)
{
	mm_segment_t old_fs;

	....
	old_fs = set_fs(KERNEL_DS);
	sys_write(1, "foo\n", 4);
	set_fs(old_fs);
	...
}

The text comes out on modprobe's standard output.

Don't tell anyone I told you this.

Re: Redirecting output

[Bodo Eggert]

shafa.hidee <shafa.hidee@gmail.com> wrote:

>      I have created a dummy module for learning device driver in linux. I
> want to redirect the standard output of printk to my xterm. But by default
> it is redirected to tty.

tail -f /var/log/syslog (or /var/log/messages)