use Test::Simple tests => 3;
use Test::Builder;
my $tb = Test::Builder->new;

systest( 0, ("who") );
systest( 0, ("who", "am", "i") );
systest( 1, ("bash", "-c", "exit 1") );

sub systest {
    my $expected = shift;
    my @cmd = @_;
    system @cmd;
    my $sysres = $? >> 8;
    $tb->is_num( $sysres, $expected, "'@cmd'" );
}