sub fred {
    # Lexical $fh is known from point of declaration (next line) to end of scope
    open(my $fh, "<", "f.tmp") or die "open error f.tmp: $!";
    # ... process file here
    # We assume no references to $fh are created in and returned from this sub
    # (if you did that reference count of $fh would not be zero on sub exit)
    # ... die might be called ... (that's ok, can be caught via block eval)
    # ... there can be multiple return statements ...
    return;
}