undefined reference to `__errno_location(void)'

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On Mon, 2 Sep 2002 07:38:48 +0100
"Rupert Wood" <me@rupey.net> wrote:

> Gordon Ellsworth wrote:
> 
> > /home/muvie/muvie/src/socket_class.c:211: undefined reference to 
> > `__errno_location(void)'
> :
> >     And when you link make sure to add -lpthread,
> >     since the symbol for errno_location is defined
> >     in the libpthread library on Linux.
> :
> > I tried this, but it did not get rid of the problem.
> 
> Can I confirm that you tried the '-lpthread' in addition to the #include
> in the PR comment? 

Which #include would that be? I think I missed it.

> If so, can you confirm that you've got a libpthread.a
> or libpthread.so in /lib or /usr/lib 

Here's what I have:
./usr/lib/libpthread.a
./usr/lib/libpthread_p.a
./lib/libpthread-0.9.so
./usr/lib/libpthread.so

> and that it contains the symbol
> __errno_location?
> 

How do I check for the symbol?

I tried this to see if the symbol was there, I don't know if this is the right
way to check:
[root@vaghn (/)] 01:02:53 $ grep "__errno_location" /usr/lib/libpthread.a
Binary file /usr/lib/libpthread.a matches
[root@vaghn (/)] 01:02:56 $ grep "__errno_location" /usr/lib/libpthread.so
Binary file /usr/lib/libpthread.so matches

> As you said you haven't upgraded, the system *ought* to work as shipped.
> But it's possible (albeit unlikely) that your C library was not build
> with threading support or that you're missing the ptherad library -
> maybe you need to install it as a separate package?

I installed every package that comes with Slackware 8.1 (I did a full install
from the Slackware CD) so there should be nothing missing.

> 
> Good luck,
> Rup.

Thank you for your help.

Sincerely,

Gordon R. Ellsworth, Jr.