I have a cpp file in which the function Open() is declared: Open(int x) { do some stuff with x; } I want to compile this as a so. So I have this: lnx626.o: lnx626.cpp g++ -fPIC -c -O -Wall lnx626.cpp g++ -shared -Wl,-soname,lib626.so -o lib626.so lnx626.o I then have my program test which has Open(1); in main(); I want to dynamically link the so file and have this: test626: 626test.o g++ -O -lpthread -Wall -o test626 626test.o -L./ -l626 why do I still get an undefined reference to Open(int)? TIA -- Best regards, David Stroupe Keyed-Up Software -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/