Just like the previous answer stated, Cwd qw(abs_path) would do the job just as realpath from the same module would do.
However, one really do not need the readlink function anymore because "..Symbolic links and relative-path components ("." and "..") are resolved to return the canonical pathname.." -- perldoc Cwd.

   use Cwd qw(abs_path realpath);
   #....

   my $absolute_path = abs_path($link);
   # or ...
   my $absolute_path = realpath($link);
[download]