Interprocess Communication (IPC)
   In general, don't directly access the system in code meant to be
   portable. That means, no "system", "exec", "fork", "pipe", ``, "qx//",
   "open" with a "|", nor any of the other things that makes being a perl
   hacker worth being.

##</code><code>##

sub auto_quote_system {
    my $line = shift;
    my @parts = split " ", $line;
    my $cmd = shift @parts;
    while ( ! -x $cmd ) {     # does -x works for file associations?
        $cmd .= " " . shift @parts;
    }
    return qq{"$cmd" @parts};
}