Re: [PATCH] change Perl syntax to support Perl 5.6

["Avery Pennarun" <apenwarr@gmail.com>]

On Sun, Aug 31, 2008 at 12:27 PM, Junio C Hamano <gitster@pobox.com> wrote:
> merlyn@stonehenge.com (Randal L. Schwartz) writes:
>
>>>>>>> "Avery" == Avery Pennarun <apenwarr@gmail.com> writes:
>>
>> Avery> Shell quoting is a disaster (including security holes, where relevant)
>> Avery> waiting to happen.  The above is the only sane way to do it, and it
>> Avery> isn't very hard to implement.  (Instead of system() in the subprocess,
>> Avery> you can use exec().)
>>
>> quotemeta() is about regex quoting.  This is not precisely the same as shell
>> quoting, and is both misleading, and potentially broken.
>
> Agreed to, and grateful for, both of your comments.
>
> Do you like the one Jakub quoted from how gitweb does it?  It looks like
> this:
>
>    # quote the given arguments for passing them to the shell
>    # quote_command("command", "arg 1", "arg with ' and ! characters")
>    # => "'command' 'arg 1' 'arg with '\'' and '\!' characters'"
>    # Try to avoid using this function wherever possible.
>    sub quote_command {
>           return join(' ',
>                       map( { my $a = $_; $a =~ s/(['!])/'\\$1'/g; "'$a'" } @_ ));
>    }

No, that's just another feeble attempt at quoting, which may or may
not be correct.  I'm not smart enough to tell.

I have a proper implementation in the 'runlock' script in gitbuilder:

    http://github.com/apenwarr/gitbuilder/tree/master/runlock

In that particular case, I wanted to handle signals carefully, so I
needed the manual fork thing even in perl 5.8.  You can safely remove
the signal handling stuff (and of course the lockfile stuff) if you
just want a minimal safe fork-exec-wait implementation in perl.

Have fun,

Avery