my $quoted = qr/
(?:(?|
    (?:
        (?:[^\\\'\ ]*(?:\\[^\ ][^\\\'\ ]*)*)
        \"
    )
    (?:
        [^\\\"]*
        (?:
            \\
            .
            [^\\\"]*
        )*
    )
    (?:\"|$)
    
    |
    
    (?:(?:[^\\\' ]*(?:\\[^ ][^\\\' ]*)*)\')(?:[^\\\']*(?:\\.[^\\\']*)*)(?:\'|$)
))
/x;