update run.sh to parse command-line options

Author: dclong

run.sh

@@ -1,3 +1,28 @@
+#!/usr/bin/env bash
+
+function run.usage(){
+    cat << EOF
+Run a script to build a portable Python environment in a container of the Docker image dclong/python-potable.
+
+Syntax: ./run.sh [-h] env_example.sh
+    -h: Print this help doc.
+    env_example.sh: A shell script which installs Python packages and create a tar.gz archive from the portable Python environment. 
+
+EOF
+}
+
+if [ "$#" -ne 1 ]; then
+    echo "The script run.sh requires exactly 1 parameter! Please refe to the help doc below."
+    echo
+    run.usage
+    exit 1
+fi
+
+if [ "$1" == "-h" ]; then
+    run.usage
+    exit 0
+fi
+
 chmod +x "$1"
 docker run \
     --hostname python-portable \