Improved installation script to run in a Windows Git Bash terminal (#282)

How is this to handle both?

Fixes #281

Author: larsgeorge-db

install.sh

@@ -2,33 +2,41 @@
 
 # This script will eventually be replaced with `databricks labs install ucx` command.
 
-# Initialize an empty array to store Python 3 binary paths
-python3_binaries=()
+# Initialize an empty array to store Python binary paths
+python_binaries=()
 
 # Split the $PATH variable into an array using ':' as the delimiter
 IFS=':' read -ra path_dirs <<< "$PATH"
 
 # Iterate over each directory in the $PATH
 for dir in "${path_dirs[@]}"; do
-    # Construct the full path to the python3 binary in the current directory
+    # Construct the full path to the python binaries in the current directory
+    python2_path="${dir}/python"
     python3_path="${dir}/python3"
 
-    # Check if the python3 binary exists and is executable
+    # Check if the python binary exists and is executable
     if [ -x "$python3_path" ]; then
-        python3_binaries+=("$python3_path")
+        python_binaries+=("$python3_path")
+    elif [ -x "$python2_path" ]; then
+        python_binaries+=("$python2_path")
     fi
 done
 
-if [ -z "${python3_binaries[*]}" ]; then
+if [ -z "${python_binaries[*]}" ]; then
     echo "[!] No Python binaries detected"
     exit 1
 fi
 
 # Check versions for all Python binaries found
 python_versions=()
-for python_binary in "${python3_binaries[@]}"; do
-    python_version=$("$python_binary" --version | awk '{print $2}')
-    python_versions+=("$python_version -> $(realpath "$python_binary")")
+for python_binary in "${python_binaries[@]}"; do
+    python_version=$("$python_binary" --version)
+    IFS=" " read -ra parts <<< "$python_version"
+    if [ "${#parts[@]}" -eq "2" ]; then
+      python_versions+=("${parts[1]} -> $(realpath "$python_binary")")
+    else
+        echo "[!] Found bad version string, skipping binary"
+    fi
 done
 
 IFS=$'\n' python_versions=($(printf "%s\n" "${python_versions[@]}" | sort -V))
@@ -37,7 +45,7 @@ py="/dev/null"
 for version_and_binary in "${python_versions[@]}"; do
     echo "[i] found Python $version_and_binary"
     IFS=" -> " read -ra parts <<< "$version_and_binary"
-    py="${parts[2]}"
+    IFS="" py="${parts[@]:2}"
 done
 
 echo "[i] latest python is $py"
@@ -46,12 +54,20 @@ tmp_dir=$(mktemp -d)
 
 # Create isolated Virtualenv with the latest Python version
 # in the ephemeral temporary directory
+echo "[i] installing venv into: $tmp_dir"
 $py -m venv "$tmp_dir"
 
-. "$tmp_dir/bin/activate"
-
-# Use the Python from Virtualenv
-py="$tmp_dir/bin/python"
+# Detect which venv this is, activate and reset Python binary
+if [ -f "$tmp_dir/bin/activate" ]; then
+    . "$tmp_dir/bin/activate"
+    py="$tmp_dir/bin/python"
+elif [ -f "$tmp_dir/Scripts/activate" ]; then
+    . "$tmp_dir/Scripts/activate"
+    py="$tmp_dir/Scripts/python"
+else
+    echo "[!] Creating Python virtual environment failed"
+    exit 1
+fi
 
 echo "[+] making sure we have the latest pip version"
 # Always upgrade pip, so that the hatchling build backend works. Hinted by errors like
@@ -68,4 +84,4 @@ $py -m pip install --quiet -e .
 # without console_scripts entrypoint
 $py -m databricks.labs.ucx.install
 
-rm -r "$tmp_dir"
+rm -r "$tmp_dir"