use IO::Scalar;
my $data;
tie *HACK, 'IO::Scalar', \$data;
print HACK <STDIN>;
tied(*HACK)->setpos(0);
*STDIN = *HACK;

##</code><code>##

use IO::Scalar;
$data = join '', <STDIN>;
my $s;
tie *STDIN, 'IO::Scalar', \$s;
print STDIN $data;
tied(*STDIN)->setpos(0);

##</code><code>##

print $data;
print <STDIN>;