Show help by default

help.go

@@ -22,11 +22,11 @@ func usage(keyMap KeyMap) string {
     curl ... | fx
 
   %v
-    -h, --help          Print help
-    -v, --version       Print version
-    --themes            Print themes
-    -r, --raw           Treat input as a raw string
-    -s, --slurp         Read all inputs into an array
+    -h, --help            print help
+    -v, --version         print version
+    --themes              print themes
+    -r, --raw             treat input as a raw string
+    -s, --slurp           read all inputs into an array
 
   %v
 %v

main.go

@@ -73,7 +73,10 @@ func main() {
 	var fileName string
 	var src io.Reader
 
-	if stdinIsTty && len(args) == 1 {
+	if stdinIsTty && len(args) == 0 {
+		fmt.Println(usage(keyMap))
+		return
+	} else if stdinIsTty && len(args) == 1 {
 		filePath := args[0]
 		f, err := os.Open(filePath)
 		if err != nil {