Added -list option

flag.go

@@ -20,12 +20,14 @@ func (i *arrayFlags) Set(value string) error {
 
 var (
 	flagVersion    bool
+	flagList       bool
 	flagIncludeAll bool
 	flagExcludeAll bool
 	flagExcept     arrayFlags
 )
 
 func init() {
+	flag.BoolVar(&flagList, "list", false, "Only list database names.")
 	flag.BoolVar(&flagVersion, "version", false, "Prints version and exits.")
 	flag.BoolVar(&flagIncludeAll, "include-all", false, "Split out all databases, with provided exceptions.")
 	flag.BoolVar(&flagExcludeAll, "exclude-all", false, "Split out no databases, with provided exceptions.")
@@ -37,6 +39,11 @@ func init() {
 		os.Exit(0)
 	}
 
+	if flagList && (flagIncludeAll || flagExcludeAll || len(flagExcept) > 0) {
+		fmt.Println("-list is not usable with any other flag.")
+		os.Exit(1)
+	}
+
 	if flagIncludeAll && flagExcludeAll {
 		fmt.Println("-include-all and -exclude-all are mutually exclusive")
 		os.Exit(1)

main.go

@@ -75,11 +75,11 @@ func main() {
 			}
 		}
 
-		if db.IsOpen() {
+		if !flagList && db.IsOpen() {
 			db.Write(line)
 		}
 
-		if dbDone.MatchString(line) {
+		if !flagList && dbDone.MatchString(line) {
 			db.Completed = true
 			db.Close()
 			prevDb = db