Question

gcc 4.7.2

Hello,

I am trying to create a shared library that uses the apr (apache portable runtime) library.

However, when I do the following I get this:

ldd libjq.so
linux-gate.so.1 =>  (0xf777b000)
libdl.so.2 => /lib/libdl.so.2 (0xf774b000)
libapr-1.so.0 => not found
libc.so.6 => /lib/libc.so.6 (0xf7599000)
/lib/ld-linux.so.2 (0x4be59000)

Cannot find it:

libapr-1.so.0 => not found

I have compiled the apr from source so that are not on the system path. I have placed the include and libs in a tools folder to be used with this project.

My directory structure looks like this:

projects/apr_queue/src/job_queue.c
projects/apr_queue/tools/lib/apr*
projects/apr_queue/tools/inc/apr*

I compile and create the object file:

cc -c -m32 -Wall -Wextra -g -I../tools/apr/inc job_queue.c -D_LARGEFILE64_SOURCE -o job_queue.o

And create the shared library like this:

cc -m32 -shared -o libjq.so -L../tools/apr/lib -lapr-1 job_queue.o

There are no linking or compile error. Just the not found for the apr-l library.

Am I missing a step here.

Many thanks for any suggestions,

Answer 1

You could either pass the directory to the linker with rpath this will add the directory to the runtime library search path

-Wl,-rpath,/path/tools/apr/lib

Or use the LD_LIBRARY_PATH enviroment variable:

$ LD_LIBRARY_PATH=/path/tools/apr/lib ldd myprog