Re: gEDA-user: 20050329 install problem

[Gene Heskett <gene.heskett@xxxxxxxxxxx>]

On Sunday 03 April 2005 15:16, Marvin Dickens wrote:
>On Sunday 03 April 2005 10:35, Charles Lepple wrote:
>> On Apr 3, 2005 8:04 AM, Stuart Brorson <sdb@xxxxxxxxxx> wrote:
>> > As for ldconfig.cache, my Fedora machine uses a file
>> > "/etc/ld.so.conf".  Does yours use ldconfig.cache?  Which one is
>> > Linux standard?
>>
>> As I understand it, /etc/ld.so.conf is the standard list of
>> directories to search for shared libraries at runtime (in the
>> absence of hard-coded paths in the executable), and when you run
>> ldconfig, it updates /etc/ld.so.cache (which is a binary file). I
>> haven't heard of ldconfig.cache-- maybe that was a typo?

I've always wondered why, after it exhausts the usual suspects list of 
libraries when its looking for a resource it needs, and you are doing 
an strace, that it wanders all over the system, wasting 150 to 200 
millisecs in seek times alone, before the cache is finally opened and 
the resource location read.  Then of course its opened ok on the next 
attempt 99.99% of the time.

To my way of thinking, it should look there first, not 8th or 10th in 
the search.  There may be valid reasons for doing it that way, but 
they haven't become obvious to me.

>In fact, as I understand it, ld.so.conf is part of the Linux
> Standard Base. RH and other distributors claim adherence to the
> LSB, but this claim is dubious. For more information, refer to:
>
>http://www.faqs.org/docs/Linux-HOWTO/Program-Library-HOWTO.html
>
>The way it's supposed to work is that the list of directories on a
> system that are to be searched are supposed to be stored in the
> file /etc/ld.so.conf.  A lot of Red Hat derived distributions  do
> not include /usr/local/lib in the file /etc/ld.so.conf. Is this a
> bug or intentional? Regardless, it's broken. You can "fix" this by
> adding /usr/local/lib to /etc/ld.so.conf.

Which I did, years ago.  But, I've been told that /lib, /usr/lib, 
and /usr/local/lib are builtin defaults.  But, I've not seen any 
evidence that the search is truely exhaustive in looking at the 
ld.so.cache here.

>The way I documentation is that ldconfig determines run-time link
> bindings between ld.so and shared libraries. ldconfig looks at your
> system and sets up the symbolic links to shared libraries. It
> creates /etc/ld.so.cache which is used to speed things up.

-- 
Cheers, Gene
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