copying application to another machine, cannot find shared library

Question

Hello

gcc 4.4.3 c89 linux

I am using log4c and have placed the inc and lib in the following directories

/home/jeff/projects/gateway/tools/log4c/inc
/home/jeff/projects/gateway/tools/log4c/lib

In my Makefile I have specified the inc and lib path:

INC_PATH = -I tools/log4c/inc
LIB_PATH = -L tools/log4c/lib
LIBS = -llog4c

In my lib directory I have the following shared libraries:

lrwxrwxrwx 1 root root     17 2010-08-26 15:57liblog4c.so -> liblog4c.so.3.1.0
lrwxrwxrwx 1 root root     17 2010-08-26 15:57 liblog4c.so.3 -> liblog4c.so.3.1.0
-rw-r--r-- 1 root root 100180 2010-08-26 15:55 liblog4c.so.3.1.0

I compile my application on my development machine, then copy the binary and tools directory to the test machine

So when I execute binary on the test machine I get the following error:

./app: error while loading shared libraries: liblog4c.so.3: cannot open shared object file: No such file or directory

However, everything works fine on my development machine which has the same directory structure i.e.

dev machine:

/projects/gateway/app
/projects/gateway/tools/log4c/inc
/projects/gateway/tools/log4c/lib

test machine:

/projects/gateway/app
/projects/gateway/tools/log4c/inc
/projects/gateway/tools/log4c/lib

So I am wondering why it can't find it the shared library.

Many thanks for any suggestions,

Answer 1

/projects/gateway/tools/log4c/lib should either be put to /etc/ld.so.conf (call /sbin/ldconfig after) or to LD_LIBRARY_PATH shell variable so the dynamic linker would know where to search for the required shared library.

See Program Library HOWTO (3.5. Installing and Using a Shared Library) for more info