[yocto] ldd

[Uwe Geuder]

Hi!

When searching for "yocto ldd" Google brings up this old posting

On Mon Nov 11 05:25:08 PST 2013 Chris Hallinan challinan at gmail.com wrote:

> On Sat, Nov 9, 2013 at 9:57 AM, Gary Thomas <gary at mlbassoc.com> wrote:
>
>> On 2013-11-09 06:42, Seth Bollinger wrote:
>>
>>> Hello All,
>>>
>>> I don't see that ldd is part of the cross toolchain build anywhere.  Am I
>>> missing something?
>>>
>>
>> It's built with the eglibc recipe and is packaged separately.
>>
>>

Right, and the command to locate it is

$ oe-pkgdata-util find-path /usr/bin/ldd
ldd: /usr/bin/ldd

So the package name is indeed ldd.

>Gosh, I though ldd, originally a hard-to-maintain script, was obsoleted a
>long time ago. This command:
>
>$ readelf --dynamic <binary>
>
>provides the same information, and readelf can be found in every cross
>toolchain.
>
>-Chris
>

I don't think that is correct. readelf only shows static information
embedded into the binary. ldd does runtime lookup obeying e.g. the
LD_LIBRARY_PATH environment variable. It also has options -r and -u for
actually doing the relocations and it will report errors if they don't
succeed. So ldd is more useful than readelf for some use cases. 

Regards,

Uwe Geuder
Neuro Event Labs Oy
Tampere, Finland
uwe.gexder at neuroeventlabs.com (Bot check: fix one obvious typo)