shared library not found while linking C program

shared library not found while linking C program

[pinafl]

hello,

i ever get that error while trying to build a C code program, calling a C-
function strored in my own shared library.

the message is:
toto.o: In function `main':
toto.o(.text+0x7): undefined reference to `function_name'
collect2: ld returned 1 exit status

GCC is called with the -L option for additionnal directory to search in.
I'd like to use the -l option to name the right library but it is not
recognised, GCC is then looking for a "-llibname" file and of course does
not find it.

Is there a particular way to create my library?
I'm working on ggc version 2.96, Red Hat Linux 7.1 2.96-98)

Any answer welcome, thanks for your help.

Florent Pinault.

Re: shared library not found while linking C program

[Paul Jarc]

<pinafl@freesurf.fr> wrote:
> GCC is called with the -L option for additionnal directory to search in.
> I'd like to use the -l option to name the right library but it is not
> recognised, GCC is then looking for a "-llibname" file and of course does
> not find it.

gcc ... /path/to/libfoo.so
is equivalent to:
gcc ... -L/path/to -lfoo.so
So use the first form if your library is not named lib*.  You'll
probably also want to add /path/to to $LD_RUN_PATH at compile time or
$LD_LIBRARY_PATH at run time, if the library isn't in one of the
system library directories.


paul

Re: shared library not found while linking C program

[Eljay Love-Jensen]

COMPILE:
gcc toto.o myOwnSharedLibrary.so -o toto.executable
(Always put the files WITH the dependency first, and the files that PROVIDE 
the linkage later in the link line.  Probably not necessary for .so files, 
but a good habit to get into.)

RUN:
LD_LIBRARY_PATH=.:$LD_LIBRARY_PATH toto.exectuable

I assume you don't have . (current working directory) in your LD_LIBRARY_PATH.

--Eljay