shell script to switch between versions of GCC ARM Embedded

switch-gcc-arm.sh

#!/bin/bash
# place in folder and add folder to $PATH
# also add $BIN to path
BIN=~/bin/gcc-arm/gcc-arm-bin
OPTIONS="4.9.3 5.4.1 6.2.1"
select opt in $OPTIONS; do
  if [ "$opt" = "4.9.3" ]; then
    echo 4.9.3 20150529
    if [ -L $BIN ]; then
      rm $BIN
    fi
    ln -s ~/bin/gcc-arm/gcc-arm-none-eabi-4_9-2015q3/bin/ $BIN
    exit
  elif [ "$opt" = "5.4.1" ]; then
    echo 5.4.1 20160919
    if [ -L $BIN ]; then
      rm $BIN
    fi
    ln -s ~/bin/gcc-arm/gcc-arm-none-eabi-5_4-2016q3/bin/ $BIN
    exit
  elif [ "$opt" = "6.2.1" ]; then
    echo 6.2.1 20161205
    if [ -L $BIN ]; then
      rm $BIN
    fi
    ln -s ~/bin/gcc-arm/gcc-arm-none-eabi-6-2017-q2-update/bin/ $BIN
    exit
  else
    clear
    echo Unknown build
    exit
  fi
done