Testing STDIN

From Perl QA

MakeMaker's test of prompt() shows how to tie STDIN.

 SKIP: {
    # Tying is less reliable on older perls.
    skip "eof() doesn't honor ties in 5.5.3", 3 if $] < 5.006;

    # close STDIN, though I don't remember why this is necessary
    close STDIN;

    # tie STDIN using TieIn
    my $stdin = tie *STDIN, 'TieIn' or die;

    # put some stuff on STDIN using TieIn->write()
    $stdin->write("From STDIN");

    # Run your code which reads from STDIN
    is( prompt("Foo?", 'Bar!'), 'From STDIN',     'from STDIN' );
 }

You can steal TieIn for yourself. http://search.cpan.org/src/MSCHWERN/ExtUtils-MakeMaker-6.36/t/lib/TieIn.pm