for x64:
export CUDA_HOME="/usr/local/cuda" 
export LD_LIBRARY_PATH="${LD_LIBRARY_PATH}:${CUDA_HOME}/lib64" 
export PATH=${CUDA_HOME}/bin:${PATH}

for x86:
export CUDA_HOME="/usr/local/cuda"
export LD_LIBRARY_PATH="${LD_LIBRARY_PATH}:${CUDA_HOME}/lib"
export PATH=${CUDA_HOME}/bin:${PATH}