fix pop3 fetching, limit recv to N bytes

cmd/recv/main.go

@@ -20,6 +20,7 @@ func main() {
 	as.Append(args.INT, "n", "limit (<1 for inf)", 10)
 	as.Append(args.STRING, "u", "username", emailer.From)
 	as.Append(args.STRING, "p", "password", emailer.Password)
+	as.Append(args.INT, "b", "dont read more than this many characters", 4096)
 	if err := as.Parse(); err != nil {
 		panic(err)
 	}
@@ -42,17 +43,17 @@ func main() {
 		panic(err)
 	}
 	for msg := range msgs {
-		b, _ := ioutil.ReadAll(io.LimitReader(msg.Body, 1024))
-		s := strings.ReplaceAll(string(b), "\r\n", " ")
-		s = strings.ReplaceAll(string(s), "\n", " ")
-		s = strings.ReplaceAll(string(s), "\r", " ")
+		b, _ := ioutil.ReadAll(io.LimitReader(msg.Body, int64(as.GetInt("b"))))
+		s := strings.ReplaceAll(string(b), "\r\n", "\n")
+		s = strings.ReplaceAll(string(s), "\n", "\n")
+		s = strings.ReplaceAll(string(s), "\r", "\n")
 		if !strings.Contains(s, " ") {
 			s = "..."
 		}
 		d, _ := msg.Header.Date()
 		d = d.In(time.Local)
 		fmt.Printf(
-			"@%+v @%+v: %+v: %s\n",
+			"@%+v @%+v: \n\t%+v: \n\t%s\n",
 			d.Format("06-01-02T15:04Z07"),
 			msg.Header.Get("From"),
 			msg.Header.Get("Subject"),

email.go

@@ -86,23 +86,29 @@ func (e *Emailer) ReadIMAP() (chan *mail.Message, error) {
 }
 
 func (e *Emailer) ReadPOP3() (chan *mail.Message, error) {
-	emails := []*mail.Message{}
+	limit := e.Limit
+	if limit < 1 {
+		limit = 1000
+	}
+	emails := make(chan *mail.Message, limit)
+	defer close(emails)
+
 	c, err := pop3.DialTLS(e.POP3)
 	if err != nil {
 		return nil, err
 	}
 	defer c.Rset()
+
 	if err := c.Auth(e.From, e.Password); err != nil {
 		return nil, err
 	}
+
 	ids, _, err := c.ListAll()
 	if err != nil {
 		return nil, err
 	}
-	for j, id := range ids {
-		if e.Limit > 0 && len(ids)-1-j >= e.Limit {
-			break
-		}
+
+	for _, id := range ids {
 		raw, err := c.Retr(id)
 		if err != nil {
 			return nil, err
@@ -111,10 +117,13 @@ func (e *Emailer) ReadPOP3() (chan *mail.Message, error) {
 		if err != nil {
 			return nil, err
 		}
-		emails = append(emails, msg)
+		select {
+		case emails <- msg:
+		default:
+			break
+		}
 	}
-	return nil, nil
-	//return emails, nil //c.Quit()
+	return emails, nil
 }
 
 func (e *Emailer) Send(to, subj, msg string) error {