Rather crude script to change between Xcode 8 and Xcode 9 selecting the correct command line tools

select-xcode.sh

#!/bin/bash

# if 1st param empty...
if [ -z "$1" ]
then
    echo "Usage: select-xcode {8|9}"
    exit
fi

XCODE8_APP=/Applications/Xcode-8.app
XCODE9_APP=/Applications/Xcode.app

du -hs ~/Library/Developer/Xcode/DerivedData/

echo "🔥  Deleting derived data..."
rm -rf ~/Library/Developer/Xcode/DerivedData/*

echo "Closing open Simulators"
killall "Simulator"
killall "Xcode"

echo "Select command line tools"

if [ $1 == "8" ]
then
sudo xcode-select -s $XCODE8_APP/Contents/Developer/
else
sudo xcode-select -s $XCODE9_APP/Contents/Developer/
fi

echo "💻  Selected Command line tools:"
xcode-select --print-path

echo "🛠  Opening Xcode"


if [ $1 == "8" ]
then
open $XCODE8_APP
else
open $XCODE9_APP
fi

Maybe '$HOME/Library/Developer/Xcode/DerivedData/' instead of '/Users/dfreniche/Library/Developer/Xcode/DerivedData/' could make the script for any user.

True. That's why it's "rather crude" :-D