Re: programming using networkmanager

[Dan Williams <dcbw redhat com>]

On Mon, 2009-08-03 at 18:40 +0200, Syed Md. Ashraful Karim wrote:
> Hi
> I want to write an application to detect any changes in the network
> interface (up and down) and the system will some task depending on that.
> Then I need the active up interfaces too. 
> Can anybody help me giving any reference how I can I handle such up/down
> of interfaces event from NetworkManager. The code can be written in Java
> or C/C++.
> thanks in advance.

Sorry for the late reply...

NetworkManager provides two methods for doing this.  First, there are
dispatcher scripts from /etc/NetworkManager/dispatcher.d that get run
whenever a device goes up or down.

Second, and preferred, is the D-Bus API.  D-Bus [1] is a lightweight IPC
mechanism that is quite popular on Linux and elsewhere.  NetworkManager
provides a dbus "service" that allows rich access and control to
networking information on your system.  The D-Bus API specification is
here [2].  The best thing to do is to find dbus bindings for language of
choice; there are bindings for both C/C++ (libdbus) and Java (dbus-java)
[3].

See (for example) the D-Bus tutorial for a better explanation of how
D-Bus IPC works [4].

Let us know if you have further questions...

Dan

[1] http://www.freedesktop.org/wiki/Software/dbus
[2] http://projects.gnome.org/NetworkManager/developers/spec.html
[3] http://dbus.freedesktop.org/doc/dbus-java/
[4] http://dbus.freedesktop.org/doc/dbus-tutorial.html