$line = <FILE>;                 #  <---------- 35
    # this line doesn't work. don't know what's wrong here..

##</code><code>##

  @buf = <FILE>;                     # you reading all lines of FILE into @buf
  foreach $line (@buf) {             # OK! (well, "my $line" would be better)
     $line = <FILE>;                 # but now reading again a single line !?! 
                                     #     which is  undef after EOF