Fill out stub of make_working_dir function

utils/lib_utils.sh

@@ -41,7 +41,21 @@ set -o nounset                              # Treat unset variables as an error
 #    PARAMETERS:  
 #       RETURNS: The path to the working directory 
 #-------------------------------------------------------------------------------
-function make_working_dir { echo; }
+function make_working_dir { 
+	# the directory of the script
+	DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+	# the temp directory used, within $DIR
+	# omit the -p parameter to create a temporal directory in the default location
+	WORK_DIR=`mktemp -d -p "$DIR"`
+
+	# check if tmp dir was created
+	if [[ ! "$WORK_DIR" || ! -d "$WORK_DIR" ]]; then
+		echo "Could not create temp dir"
+		exit 1
+	fi
+	echo $WORK_DIR
+ }
 
 #---  FUNCTION  ----------------------------------------------------------------
 #          NAME:  clean_working_dir