babel: update searx_extra/update/update_translations.sh

the script expects searx/translations/messages.pot to be commited

it calls "pybabel extract", and if there is a meaningful change,
it calls "pybabel update"

exit code 0 when there is a change in messages.pot

searx_extra/update/update_translations.sh

@@ -1,15 +1,28 @@
-#!/bin/sh
+#!/usr/bin/env bash
+# -*- coding: utf-8; mode: sh indent-tabs-mode: nil -*-
 
 # script to easily update translation language files
 
 # add new language:
-# pybabel init -i messages.pot -d searx/translations -l en
+# pybabel init -i searx/translations/messages.pot -d searx/translations -l en
 
-SEARX_DIR='searx'
+APP_DIR="searx"
+TRANSLATIONS="${APP_DIR}/translations"
+MESSAGES_POT="${TRANSLATIONS}/messages.pot"
 
-pybabel extract -F babel.cfg -o messages.pot "$SEARX_DIR"
-for f in `ls "$SEARX_DIR"'/translations/'`; do
-    pybabel update -N -i messages.pot -d "$SEARX_DIR"'/translations/' -l "$f"
-done
+get_sha256() {
+    echo "$(grep "msgid" "${MESSAGES_POT}" | sort | sha256sum | cut -f1 -d\ )"
+}
 
+EXISTING_SHA="$(get_sha256)"
+
+pybabel extract -F babel.cfg -o "${MESSAGES_POT}" "${APP_DIR}"
+
+if [ "$(get_sha256)" = "${EXISTING_SHA}" ]; then
+    echo '[!] no changes detected, exiting']
+    exit 1
+fi
+
+pybabel update -N -i "${MESSAGES_POT}" -d "${TRANSLATIONS}"
 echo '[!] update done, edit .po files if required and run pybabel compile -d searx/translations/'
+exit 0