use strict;
use warnings;

my $include_file = 'include.pl';

my $wibble;

eval do {
   open(my $fh, '<', $include_file)
      or die("Unable to open include \"$include_file\": $!\n");
   local $/;
   <$fh>
};
die $@ if $@;

print $wibble;

##</code><code>##

# include.pl

$wibble = 'fred';

# Uncommenting the following line causes a strict error.
#$wobble = 'joe';