improve docs

cmd/any2anexoj-cli/main.go

@@ -25,7 +25,7 @@ var (
 	format   = pflag.StringP("format", "f", "table", "Output format: table or csv")
 	ofAPIKey = pflag.String("open-figi-api-key", "", "An OpenFIGI API key for faster report generation (better rate api rate limits)")
 	// TODO: improve documentation on selectors
-	selectors = pflag.StringSlice("selectors", nil, "Only process entries that conform to all the selectors:")
+	selectors = pflag.StringSlice("selectors", nil, "Only process entries that conform to all the selectors: code, assetCountry")
 )
 
 func main() {
@@ -51,13 +51,11 @@ func run(ctx context.Context) error {
 	slog.SetDefault(slog.New(slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{Level: logLevel})))
 
 	if platform == nil || len(*platform) == 0 {
-		slog.Error("--platform flag is required")
-		os.Exit(1)
+		return fmt.Errorf("--platform flag is required")
 	}
 
 	if lang == nil || len(*lang) == 0 {
-		slog.Error("--language flag is required")
-		os.Exit(1)
+		return fmt.Errorf("--language flag is required")
 	}
 
 	reader, err := getReader(*platform, *ofAPIKey)