use strict;
use warnings;

open my $msg, "+>", \my $message or die "no message $!";

print $msg " foo\n";
print $msg " bar\n";

print "\$message:\n$message";

seek $msg, 0, 0;  # reset filepointer
my $text;
while (my $line = <$msg>) {
    $text .= $line;
}

print "\$text:\n$text";

##</code><code>##

$message:
 foo
 bar
$text:
 foo
 bar