Notification as popups when a file being written

I would like to know
Is it possible to get a notification as pop-up in linux
when a folder with extension '.aqs' written
a popup should come
as " The folder has been written "

Thank you in advance

So whenever anyone writes any file named .aqs, you want a notification?

It might be possible in C, on certain systems, but it's not really a shell scripting thing.

What's your system?

linux ( Centos )

Centos alone isn't very helpful. The output of uname -a would have been better.

If it's supported by your kernel, you can use inotify.

inotify(7): monitoring file system events - Linux man page

For shell script use, inotifywait from inotify-tools may be of interest.

inotifywait(1) - Linux man page

Popular scripting languages also provide their own inotify interfaces.

Beyond watching the filesystem, as for delivering the gui notification itself, that probably depends on the desktop environment you're using and/or if there's a specific daemon with which to communicate.

Regards,
Alister

inotify is not there in my system.....

In case you misunderstand, inotify isn't a command. It's a kernel interface.

As for your system, we still don't know what it is. If you want help, the least you will have to do is to precisely identify your platform.

Regards,
Alister