error while loading shared libraries

问题

Thank you guys answering my previous problem on undefined reference to function. As you suggested, the reason under the problem is not linking the libraries. Now I have generated the executable file with: (the version of my g++ and gcc is 4.4.5. I am using Ubuntu 10.10.)

g++ -o ex_addinst  ./ex_addinst.o -L/home/li/work/tools/lindo/lindoapi/bin/linux64 -m64 -llindo64  -lmosek64 -lconsub3 -lc -ldl -lm -lguide -lpthread -lsvml -limf -lirc

But there comes another problem, when I run the executable file with

./ex_addinst

errors appear: (I am not sure I should start a new problem or not currently....)

./ex_addinst: error while loading shared libraries: liblindo64.so.6.0: cannot open shared object file: No such file or directory

But liblindo64.so.6.0 exists in the folder of the lib ~/lindoapi/bin/linux64 which contains following files:

libconsub3.so  libirc.so          liblindojni.so        libmosek64.so.5.0  lindo.par
libguide.so    liblindo64.so      liblindojni.so.6.0.3  libsvml.so         placeholder
libimf.so      liblindo64.so.6.0  libmosek64.so         lindoapivars.sh    runlindo

I have created a symbolic link between liblindo.so.6.0 and liblindo.so:

ln -sf liblindo64.so.6.0 liblindo64.so

There is '-llindo64' is the g++ command, so I thought liblindo64.so.6.0 should have been linked. I have tried to change -L to -Llib, but doesn't help.

Can anyone tell me what is wrong here? Thanks!

回答1:

You need to have the directory where the .so files live in in runtime linker's search path.

You can do that by changing the LD_LIBRARY_PATH environment variable like this:

export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:$HOME/lindoapi/bin/linux64

before starting your executable.

回答2:

If you are not going to install libraries currently under /home/li/work/tools/lindo/lindoapi/bin/linux64 into a system directory (/usr/lib, /usr/local/lib, etc.), then it is better to simply link the application such that it will just work(TM):

gcc -o ex_addinst  ./ex_addinst.o \
  -L/home/li/work/tools/lindo/lindoapi/bin/linux64 \
  -Wl,-rpath=/home/li/work/tools/lindo/lindoapi/bin/linux64 \
  -m64 -llindo64  -lmosek64 -lconsub3 -lc -ldl \
  -lm -lguide -lpthread -lsvml -limf -lirc

This is preferable to always having to set LD_LIBRARY_PATH, because

other people can run your executable (without having to set LD_LIBRARY_PATH) and,
it doesn't slow down all the other applications (otherwise they will all search LD_LIBRARY_PATH for libc.so.6, etc.)

The reason your LD_LIBRARY_PATH setting didn't work (comment to Mat's answer) is that you used HOME where /home was intended.

回答3:

to sum the solution:

I add the path to ~./bashrc with:

export LD_LIBRARY_PATH=${LD_LIBRARY_PATH}:$HOME/.../lindoapi/bin/linux64
(after generating .o file)link the objective file with:

g++ -o ex_addinst ./ex_addinst.o -L/home/.../lindoapi/bin/linux64 -m64 -llindo64 -lmosek64 -lconsub3 -lc -ldl -lm -lguide -lpthread -lsvml -limf -lirc

来源：https://stackoverflow.com/questions/7455601/error-while-loading-shared-libraries

标签

bash

shared-libraries