Progress bar while coping a file needed.

Hi guys I want to create a script which will show the amount of data that is been copied from one location to another location.

For example:
Say i have a file called abc.img which is approximately 4 gb of size therfore everytime i copy the file from one location to another i want a progress bar to appear like 50% completed 51% completed and so on.

I have no idea how to establish that.
Please give some suggestion on this.

what have you tried till now??

No idea where to start

zenity --progress ?
here a thread about using it in copying files.
what you have to do is to get the fullsize of the file and the size of what has already has beeen copied and then :

Fullsize=$(stat -c %s $file1)
(   
    CopiedBytes=$(stat -c %s $file2)
    let Percentage=CopiedBytes*100/Fullsize
    echo $Percentage
    sleep 1
) | zenity --progress --title="Copying files" --text="Copying $file1 to $file2" --percentage=0 --autoclose

Not tested but should work