Hi,
I have an application which talks to the database using the ODBC APIs.
In this I use the dlopen function to open the ODBC driver
manager(libodbc.so) which generally is a .so file(on Solaris, Linux)
On AIX I donnot have a .so file but have a libodbc.a which internally
maps to another file called the odbc.so (which has all the symbols
which generally should be present under the libodbc.so)
In the app I try to open the libodbc.so using the dlopen which is
succesfully executed. All the calls to the dlsym function are also
successful. But None of the functions which are part of the ODBC
driver are working.
I have read on the net that there are some problems with the usage of
the shared objects on the AIX machine. My questions:
1) Since I donnot have a .so (libodbc.so) file is it right to pass
this as an argument to the dlopen function
2) How is it that the dlopen and the slsym function are not giving
errors and still I am not able to use the function present in the
library
3) Is there any work around to make this work

phil_pp1@yahoo.com (Philips P) writes:

> I have an application which talks to the database using the ODBC APIs.
> In this I use the dlopen function to open the ODBC driver
> manager(libodbc.so) which generally is a .so file(on Solaris, Linux)
> On AIX I donnot have a .so file but have a libodbc.a which internally
> maps to another file called the odbc.so

Huh? What do you mean "internally maps"?

I suspect libodbc.a simply *contains* odbc.so (you can verify this
with "ar tv libodbc.a"), in which case you should be calling

dlopen("libodbc.a(odbc.so)", RTLD_LAZY|RTLD_MEMBER);

> In the app I try to open the libodbc.so using the dlopen which is
> succesfully executed.

This will *not* open libodbc.a. If it returns success, then somewhere
on your system you have libodbc.so, which may not be the library
you want to dlopen().

> All the calls to the dlsym function are also
> successful. But None of the functions which are part of the ODBC
> driver are working.

Perhaps libodbc.so contains "do-nothing" stubs, and was intended
for something else?

> I have read on the net that there are some problems with the usage of
> the shared objects on the AIX machine.

There are no problems with "usage of shared objects" on AIX.
It's just that they work differently from every other UNIX.

> 1) Since I donnot have a .so (libodbc.so) file is it right to pass
> this as an argument to the dlopen function

No. See above.

> 2) How is it that the dlopen and the slsym function are not giving
> errors and still I am not able to use the function present in the
> library

See above.

> 3) Is there any work around to make this work

Yes: if you want to open libodbc.a, you must call dlopen() with
correct parameters.

Cheers,
--
In order to understand recursion you must first understand recursion.
Remove /-nsp/ for email.