Check env and cmdline provided config file paths

Look for config files in the paths specified on commandline and
by environment variable. If found, skip deploying template
files prior to attempting generation of SQLite file.

refs WhyAskWhy/mysql2sqlite#3

bin/create_db.sh

@@ -22,18 +22,6 @@ THIS_DEV_ENV_GIT_REPO_BRANCH="master"
 general_config_file="mysql2sqlite_general.ini"
 query_config_file="mysql2sqlite_queries.ini"
 
-# Attempt to emulate approach that would be used to pass in a dir path
-# to the main script.
-cmdline_dir_value=$1
-
-config_file_dirs=(
-    "${cmdline_dir_value}"
-    "/etc/mysql2sqlite"
-    "~/.config/mysql2sqlite"
-    "/tmp/${MAIN_PROJECT_GIT_REPO_BASENAME}"
-)
-
-
 # Get updated repo contents
 if [[ ! -d /tmp/${MAIN_PROJECT_GIT_REPO_BASENAME} ]]; then
     cd /tmp
@@ -58,16 +46,39 @@ fi
 sudo mkdir -vp /var/cache/mysql2sqlite
 sudo chown -vR ${USER}: /var/cache/mysql2sqlite
 
+# Array of directory paths to check for existing config files. If not found,
+# this script will deploy the provided templates. Entries are added to the
+# array based on the same precedence set by the main script.
+declare -a CONFIG_FILE_DIRS
+
+# Attempt to source the same environment variable that the main script will
+# attempt to use for evaluating config files
+if [[ ! -z "${MYSQL2SQLITE_CONFIG_DIR+x}" ]]; then
+    echo "Environment variable for specifying config files dir found: ${MYSQL2SQLITE_CONFIG_DIR}"
+    CONFIG_FILE_DIRS+=("${MYSQL2SQLITE_CONFIG_DIR}")
+fi
+
+# Attempt to emulate approach that would be used to pass in a dir path
+# to the main script.
+if [[ ! -z "${1+x}" ]]; then
+    echo "Command line config files dir path specified: ${1}"
+    CONFIG_FILE_DIRS+=("${1}")
+fi
+
+CONFIG_FILE_DIRS+=("/tmp/${MAIN_PROJECT_GIT_REPO_BASENAME}")
+CONFIG_FILE_DIRS+=("$HOME/.config/mysql2sqlite")
+CONFIG_FILE_DIRS+=("/etc/mysql2sqlite")
+
 config_files_found="false"
 config_files_path=""
 # Deploy template config files locally if not already present elsewhere
-for config_file_dir in "${config_file_dirs[@]}"
+for CONFIG_FILE_DIR in "${CONFIG_FILE_DIRS[@]}"
 do
-    echo "Checking $config_file_dir for config files ..."
-    if [[ -f "${config_file_dir}/${general_config_file}" ]] && \
-       [[ -f "${config_file_dir}/${query_config_file}" ]]; then
+    echo "Checking $CONFIG_FILE_DIR for config files ..."
+    if [[ -f "${CONFIG_FILE_DIR}/${general_config_file}" ]] && \
+       [[ -f "${CONFIG_FILE_DIR}/${query_config_file}" ]]; then
         config_files_found="true"
-        config_files_path="${config_file_dir}"
+        config_files_path="${CONFIG_FILE_DIR}"
         break
     fi
 done