[bash function] change environment variable CC/CXX (.bashrc)

chcc.bashrc

function chcc {
    case "$1" in
        --unset)        unset CC ; unset CXX ;;

        clang)          export CC=clang                     ; export CXX=clang++                    ;;
        gcc)            export CC=gcc                       ; export CXX=g++                        ;;
        distcc)         export CC=distcc                    ; export CXX=distcc                     ;;
        llvm-gcc)       export CC=llvm-gcc                  ; export CXX=llvm-g++-                  ;;
        llvm-gcc-4.8)   export CC=llvm-gcc-4.8              ; export CXX=llvm-g++-4.8               ;;
        arm)            export CC=arm-linux-gnueabi-gcc     ; export CXX=arm-linux-gnueabi-g++      ;;
        armhf)          export CC=arm-linux-gnueabihf-gcc   ; export CXX=arm-linux-gnueabihf-g++    ;;
        mingw64)        export CC=x86_64-w64-mingw32-gcc    ; export CXX=x86_64-w64-mingw32-g++     ;;

                    # ex) chcc -m32
        -*)         [ "$CC" = "" ] || export CC="$CC $1"
                    ;;

        /*)         local option=$( echo "$1" | sed 's/./-/' )
                    [ "$CXX" = "" ] || export CXX="$CC $option"
                    ;;

                    # ex) chcc +ccache
        +*)         local prefix=$( echo "$1" | sed 's/.//' )
                    [ "$CC"  = "" ] || export CC="$prefix $CC"
                    [ "$CXX" = "" ] || export CXX="$prefix $CXX"
                    ;;

        "")         ;;

        *)          echo "invalid argument: '$1'" 1>&2 ;;
    esac

    echo "CC=$CC"
    echo "CXX=$CXX"
}