open(my $fh, '<', \<<'__EOI__');
...
...
...
__EOI__

##</code><code>##

my %files = (
   users => <<'__EOI__',
...
...
...
__EOI__
   posts => <<'__EOI__',
...
...
...
__EOI__
);

open(my $fh_users, '<', \$files{users});
open(my $fh_posts, '<', \$files{posts});