my $dir = "INPUT";
my $pattern = '.txt';
opendir DIR, $dir or die "cant open dir";
my @files = grep /\.txt/,(readdir DIR);
closedir DIR;
#print "@files\n";
foreach my $file (@files){
    print "$file\n";
    open (INF, $file)||warn "Can not open $file";
    $data=join ("", <INF>);
    print "$data\n";
 }