First, I can't really read your post well. Could
you put the logmessages between CODE brackets?
Then, I see you got two messages, both for different
problems.
1) File does not exist: /var/www/html/data:
Your script (http://localhost/cgi-bin/index.pl)
has made some html, and put this out to the browser.
In this html it defines an image located at '/var/www/html/data',
and this path doesn't exists. If it had existed
there would still be a problem because 'data' would
probably be a directory, not an image.
2) index.pl: Use of uninitialized value:
Here's only one variable on the line, $file. Before
you can do something like use it to open a file, you
must/should assign it a value. Try:
my $file = 'somfile';
Good luck