Re: some question about "/sys/class/net//operstate"

[Cong Wang]

On Tue, Nov 10, 2020 at 8:32 PM 杜英杰 <leon...@pku.edu.cn> wrote:
>
> I want to use inotify to monitor /sys/class/net//operstate  to detect status 
> of a iface in real time.
> when I ifdown &amp;&amp; ifup eth3, the content of operstate changed, but the 
> file's Modify time didn't change.
> I don't know the reason, is there any file which can be monitored by inotify 
> to get iface status in real time?
> Much appreciation for any advice!

You need to listen to netdev netlink messages for changes like
this. These messages are generated in real-time.

Thanks.