examine grap exit code too and printf accordingly

libisoburn/trunk/releng/run_all_releng

@@ -87,9 +87,23 @@ fi
       LIST_KWD="(NEVER|ABORT|FATAL|FAILURE|MISHAP|SORRY|WARNING|HINT|NOTE|DEBUG|ALL)"
 
       if [ -f "${CLOG}" ]; then
+          set +e
+	  # lines, perl regex, leading tabs
           grep -n -PT "${LIST_KWD}" "${CLOG}"
+	  RET_GREP="$?"
+          case ${RET_GREP} in
+              0) # found
+                 ;;
+              1) # not found
+		 printf "\n${SELF}: Log file looks clear.\n"
+                 ;;
+	      *) #
+                 printf "\n${SELF}: grep returned EXIT CODE: ${RET_GREP}.\n"
+		 ;;
+          esac
+	  set -e
       fi
-      printf "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n"
+      printf "\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n"
  fi
 
  exit 0