#! perl -slw
use strict;
use IO::Detect qw[ is_filehandle ];

sub funcTakesIO1 {
    my $fh = shift;

    if( is_filehandle( $fh ) ) {
        print $fh 'Bang!';
    }
    return;
}

sub funcTakesIO2 {
    my $fh = shift;

    if( is_filehandle( $fh ) ) {
        return <$fh>;
    }
    return;
}


eval {
    funcTakesIO1( \*STDIN );
} or warn "IO::Detect detected the wrong thing";

eval {
    funcTakesIO2( \*STDOUT );
} or warn "IO::Detect detected the wrong thing";

__END__
C:\test>junk5
Filehandle STDIN opened only for input at C:\test\junk5.pl line 9.
IO::Detect detected the wrong thing at C:\test\junk5.pl line 24.
Filehandle STDOUT opened only for output at C:\test\junk5.pl line 18.
IO::Detect detected the wrong thing at C:\test\junk5.pl line 28.