my $OSTY;
if (not exists $ENV{OSTYPE}) {
    warn "Couldn't determine OSTYPE";
    $OSTY = "<unknown>";
} else {
    $OSTY = $ENV{OSTYPE}
};

##</code><code>##

print "Running under $^O";

##</code><code>##

my $OSTY;
if (not exists $ENV{OSTYPE}) {
    warn "Couldn't determine OSTYPE from environment - using $^O";
    $OSTY = $^O;
} else {
    $OSTY = $ENV{OSTYPE}
};