i dont see the mistake in the code....

Here's one:

while (<@data>) {

The angle braces either perform readline or glob, neither of which you want here. You appear to intend to write:

while (@data)

... but that's not going to work very well because the last line of the block is:

   push(@data,$_);

... so you'd create an infinite loop.

Iterate over the filehandle instead of @data and you'll have more success.