UT 123456789
1234
9876
1234
some additional string information
THE_END
UT 987654321
1234
2345
some additional string information
THE_END
UT 1928374756
4321
2567
1234
THE_END
some additional string information
UT 5647382910
1234
2435
5678
some additional string information
THE_END

##</code><code>##

#!perl

use strict;
use warnings;
use FindBin;

my $dir ="$FindBin::Bin/../rxo";
opendir(my $dh, $dir) || die "can't opendir $dir: $!"; 
my @inputs = readdir($dh);
closedir $dh;
splice @inputs, 0, 2;

my @dispatch;
foreach(@inputs) {
    my $outfile = "$FindBin::Bin/../blocks/$_";
    open my $ofh, '>', $outfile || die; 
    my $file = "$FindBin::Bin/../rxo/$_";
    open my $fh, '<', $file || die;;
    my $regex = <$fh>;
    close $fh;
    push @dispatch, { file => $ofh, regex => qr/$regex/ };
    }

while(my $line = do { local $/ = 'THE_END'; <> }) {
   foreach (@dispatch) {
        print { $_->{file} } $line if $line =~ $_->{regex};
    }
}