shell if else 使用

sudo apt-get install libsoil-dev libglm-dev libassimp-dev libglew-dev libglfw3-dev libxinerama-dev libxcursor-dev libxi-dev libfreetype6-dev
sudo apt-get install g++ git
ordir=$(pwd)
echo $ordir
dir=$(cd '../../'; pwd)
dir2=$dir/opengl-demo
#echo $dir2
if [ ! -d "$dir2" ]
then
    echo "no exit opengl-demo"
    cd $ordir
    cd ../
    mkdir build_opengl_function_demo
    cd build_opengl_function_demo
    cmake ../opengl_function_demo
    make -j4
    #mkdir temp
    cp ../LearnOpenGL3.3/configure.sh ./
 
    echo -e "\nbuild finish..............."
    echo "go to ../build_opengl_function_demo and start run test case"
    #echo "1. source configure.sh"
    echo " cd bin/  start run your case"
else
    cd ../../
    mkdir build_opengl_function_demo
    cd build_opengl_function_demo
    cmake ../opengl-demo/opengl_function_demo
    make -j4
    #mkdir temp
    cp ../opengl-demo/LearnOpenGL3.3/configure.sh ./
 
    echo -e "\nbuild finish..............."
    echo "go to ../../build_opengl_function_demo and start run test case"
    #echo "1. source configure.sh"
    echo " cd bin/  start run your case"
fi

shell 中 条件判断的使用和自定义变量