New option: -ff FILENAME: post utf8 string from a file("-" means STDIN)

cmd/mstdn/main.go

@@ -24,8 +24,17 @@ import (
 var (
 	toot     = flag.String("t", "", "toot text")
 	stream   = flag.Bool("S", false, "streaming public")
+	fromfile = flag.String("ff", "", "post utf-8 string from a file(\"-\" means STDIN)")
 )
 
+func readFile(filename string) ([]byte, error) {
+	if filename == "-" {
+		return ioutil.ReadAll(os.Stdin)
+	} else {
+		return ioutil.ReadFile(filename)
+	}
+}
+
 func extractText(node *html.Node, w *bytes.Buffer) {
 	if node.Type == html.TextNode {
 		data := strings.Trim(node.Data, "\r\n")
@@ -136,6 +145,19 @@ func main() {
 		}
 		return
 	}
+	if *fromfile != "" {
+		text, err := readFile(*fromfile)
+		if err != nil {
+			log.Fatal(err)
+		}
+		_, err = client.PostStatus(&mastodon.Toot{
+			Status: string(text),
+		})
+		if err != nil {
+			log.Fatal(err)
+		}
+		return
+	}
 
 	if *toot != "" {
 		_, err = client.PostStatus(&mastodon.Toot{