[syslinux] CHDIR Directive?

Shao Miller sha0.miller at gmail.com
Fri Dec 14 12:28:11 PST 2012


On 12/12/2012 21:00, H. Peter Anvin meant to write:
> On 12/12/2012 01:27 PM, Shao Miller wrote:
>> Perhaps it could be useful to have a "CHDIR" config-file directive?  I'm
>> thinking it'd override anything passed by config.c32.  I'm also thinking
>> it'd be a config-file-global, rather than a LABEL-specific, option.
>> Then a
>> config-file could set its own working directory without using
>> config.c32 as
>> an intermediate step.  Does this seem like a reasonable feature to
>> have?  -
>> Shao
>>
>> P. S. Maybe this already exists and I haven't read about it.  If so, then
>> oops.
>>
>
> The problem with CHDIR is that it makes it very hard to deal with the
> fact that it suddenly matters "when" a certain path is interpreted. The
> reason this is currently mixed with the CONFIG directive is that that is
> a natural reset point anyway.

Yes, this makes perfect sense for why it doesn't quite seem worth the 
effort and additional complication.  I have to admit that it was a bit 
of an X Y question while thinking about a recent thread...  I wondered 
if such a directive might have its own merit(s), however.

In regards to the X in the X Y, my impression is that it's not generally 
safe to "backtrack" in a URI, but appending is safe.  In other words, 
given a CWD of:

   http://webserver/some/path/

we would turn '../' into:

   http://webserver/some/path/../

(which my web-server handles just fine) instead of:

   http://webserver/some/

I just assume that the opacity of the URI CWD is the reason for this. 
(<- ?)  Of course, one can reset the CWD to a totally new URI.

- Shao Miller


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