How to know whether a dev file has been opened or not?

asahlot · 03-05-2007, 05:31 AM

Hi All

Inside my driver init code I want to know whether a dev file like /dev/video has been opened by some application or not?
How can I do that?
Could any body please help? I need to know urgently.
Thanks in advance.

ASAHLOT

akudewan · 03-05-2007, 05:59 AM

I think the "lsof" bash command can do this.

For instance, when I run: lsof /dev/snd/* I get this output:

Code:

akudewan@ranjan404:~ $ lsof /dev/snd/*
COMMAND  PID     USER   FD   TYPE DEVICE SIZE NODE NAME
kicker  5660 akudewan   13u   CHR  116,8      7874 /dev/snd/controlC0
gkrellm 5701 akudewan    9u   CHR  116,8      7874 /dev/snd/controlC0

Edit: Note that kicker and gkrellm have volume control applets

asahlot · 03-05-2007, 11:02 PM

But I cannot run any command inside module init code.