[ELF]Dynamic Library Search Order

Dynamic Library Search Order:

1. DT_RPATH in the ELF binary, unless DT_RUNPATH set.
2. LD_LIBRARY_PATH entries, unless setuid/setgid
3. DT_RUNPATH in ELF binary
4. /etc/ld.so.cache entries, unless -z nodeflib given at link time
5. /lib, /usr/lib unless -z nodeflib
6. Done, "not found".

http://stackoverflow.com/questions/7967848/use-rpath-but-not-runpath