这个杀伤力有点大，影响范围比较广，不到万不得已不要用。
C_INCLUDE_PATH=/home/qj/crosstool_ng/.build/arm-unknown-linux-gnueabi/build/static-target/include:$C_INCLUDE_PATH
export C_INCLUDE_PATH
库文件的搜索路径:
LIBRARY_PATH=/home/qj/crosstool_ng/.build/arm-unknown-linux-gnueabi/build/static-target/lib
export LIBRARY_PATH
链接程序ld使用的库文件搜索路径：
LD_LIBRARY_PATH=/home/qj/crosstool_ng/.build/arm-unknown-linux-gnueabi/build/static-target/lib
export LD_LIBRARY_PATH