Fix Xcode-CLT install

 - software update technique wasn't finding developer tools/Xcode-CLT
 - use `return 0` to bail out of first function when this happens...
   this is normal behavior
 - make messages clearer while xcode-clt install is attempted
 - fix spelling errors

Author: zbeekman

prerequisites/install-functions/install-xcode-clt.sh

@@ -4,7 +4,7 @@ need_xcodeCLT() {
     echo "false"
   else
     local xcode_dir
-    xcode_dir="$(/usr/bin/xcode-select -print-path 2>/dev/null)"
+    xcode_dir="$(/usr/bin/xcode-select -print-path 2>/dev/null)" || true
     if [[ ! -d "${xcode_dir}" || ! -x "${xcode_dir}/usr/bin/make" ]]; then
       echo "true"
     else
@@ -14,57 +14,62 @@ need_xcodeCLT() {
 }
 
 xcode_clt_install () {
-  info "It appears that you are on Mac OS and do not have the Xcode command line tools (CLT) installed."
-  app_store_label="$(softwareupdate -l | grep -B 1 -E "Command Line (Developer|Tools)" | awk -F"*" '/^ +\\*/ {print $2}' | sed 's/^ *//' | tail -n1)"
+  app_store_label="$(softwareupdate -l | grep -B 1 -E "Command Line (Developer|Tools)" | awk -F"*" '/^ +\\*/ {print $2}' | sed 's/^ *//' | tail -n1)" || return 0
   if [[ "${arg_y}" == "${__flag_present}" ]]; then
     info "-y or --yes-to-all flag present. Proceeding with non-interactive download and install."
   else
+    info "If you proceed with the Xcode-CLT installation you may be prompted for your password."
     printf "Ready to install %s? (Y/n)" "${app_store_label}"
     read -r install_xcodeclt
     printf '%s\n' "${install_xcodeclt}"
     if [[ "${install_xcodeclt}" == [nN]* ]]; then
-      emergency "${this_script}: Aborting: cannot procede without XCode CLT."
+      emergency "${this_script}: Aborting: cannot proceed without XCode CLT."
     fi
   fi
-  info "We will attempt to download and install XCode CLT for you now. Note: sudo priveledges required"
+  info "install.sh will attempt to download and install XCode CLT for you now."
+  info "Note: sudo privileges required. Please enter your password if prompted."
   place_holder="/tmp/.com.apple.dt.CommandLineTools.installondemand.in-progress"
   sudo /usr/bin/touch "${place_holder}" || true
-  sudo /usr/sbin/softwareupdate -i app_store_label || true
+  sudo /usr/sbin/softwareupdate -i app_store_label || return 0
   sudo /bin/rm -f "${place_holder}" || true
-  sudo /usr/bin/xcode-select --switch "/Library/Developer/CommandLineTools" || true
+  sudo /usr/bin/xcode-select --switch "/Library/Developer/CommandLineTools" || return 1
 }
 
 headless_xcode_clt_install () {
-  # Fallback her if headless install failed
+  # Fallback here if headless install/upgrade failed. This is the usual path through this code.
   if [[ "${arg_y}" == "${__flag_present}" ]]; then
     info "-y or --yes-to-all flag present. Proceeding with non-interactive download and install."
   else
+    info "If you proceed with the Xcode-CLT installation you may be prompted for your password."
     printf "Ready to install Xcode-CLT using xcode-select? (Y/n)"
     read -r install_xcodeclt
     printf '%s\n' "${install_xcodeclt}"
     if [[ "${install_xcodeclt}" == [nN]* ]]; then
-      emergency "${this_script}: Aborting: cannot procede without XCode CLT."
+      emergency "${this_script}: Aborting: cannot proceed without XCode CLT."
     fi
   fi
-  info "Installing Xcode Command Line Tools (CLE), please follow instructions on popup window."
+  info "Installing Xcode Command Line Tools (CLT), using \`xcode-select --install\`."
+  info "Note: sudo privileges required. Please enter your password if prompted."
   sudo /usr/bin/xcode-select --install || emergency "${this_script}: unable to run \`sudo xcode-select --install\`"
-  printf "Press <enter> once installation has completed"
+  printf "Please press <enter> once installation of Xcode command line tools has completed."
   read -r
   sudo /usr/bin/xcode-select --switch "/Library/Developer/CommandLineTools" || \
     emergency "${this_script}: Xcode-CLT installation and activation failed, unable to continue"
 }
 
 maybe_install_xcodeCLT () {
   if [[ "$(need_xcodeCLT)" == "true" ]]; then
-    xcode_clt_install
+    info "It appears that you are on Mac OS and do not have the Xcode command line tools (CLT) installed, or they need to be upgraded."
+    info "install.sh will now attempt to install/upgrade the Xcode-CLT using \`softwareupdate\`"
+    xcode_clt_install || true # This usually fails since `softwareupdate -i` doesn't return CLTs needing update
   fi
   if [[ "$(need_xcodeCLT)" == "true" ]]; then
-    info "First Xcode-CLT installation failed, trying another method"
-    headless_xcode_clt_install
+    info "\`softwareupdate\` installation/upgrade failed. This is normal. Now trying with \`xcode-select --install\`"
+    headless_xcode_clt_install || emergency "${this_script}: Could not install Xcode command line tools, unable to proceed. Please install them via the app store before retrying this installation."
   fi
 
   clang_output="$(/usr/bin/xzrun clang 2>&1)" || true
   if [[ "${clang_output}" =~ license ]]; then
-    emergency "${this_script}: It appears you have not agreed to the Xcode license. Please do so before attempting to run this script again. This may be acheived by opening Xcode.app or running \`sudo xcodebuild -license\`"
+    emergency "${this_script}: It appears you have not agreed to the Xcode license. Please do so before attempting to run this script again. This may be achieved by opening Xcode.app or running \`sudo xcodebuild -license\`"
   fi
 }