my @file_lines = <$match>; 
$Hash_filenames{$plf} = \@file_lines;

##</code><code>##

$Hash_filenames{$plf} = [ <$match> ];

##</code><code>##

$Hash_filematches{$filename} = [
   grep( /\/\Q$file_name\E#/i, @{ $Hash_filenames{$plf} } )
];