Data commit

Task/Send-email/Go/send-email.go

@@ -0,0 +1,161 @@
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"net/smtp"
+	"os"
+	"strings"
+)
+
+type Message struct {
+	From    string
+	To      []string
+	Cc      []string
+	Subject string
+	Content string
+}
+
+func (m Message) Bytes() (r []byte) {
+	to := strings.Join(m.To, ",")
+	cc := strings.Join(m.Cc, ",")
+
+	r = append(r, []byte("From: "+m.From+"\n")...)
+	r = append(r, []byte("To: "+to+"\n")...)
+	r = append(r, []byte("Cc: "+cc+"\n")...)
+	r = append(r, []byte("Subject: "+m.Subject+"\n\n")...)
+	r = append(r, []byte(m.Content)...)
+
+	return
+}
+
+func (m Message) Send(host string, port int, user, pass string) (err error) {
+	err = check(host, user, pass)
+	if err != nil {
+		return
+	}
+
+	err = smtp.SendMail(fmt.Sprintf("%v:%v", host, port),
+		smtp.PlainAuth("", user, pass, host),
+		m.From,
+		m.To,
+		m.Bytes(),
+	)
+
+	return
+}
+
+func check(host, user, pass string) error {
+	if host == "" {
+		return errors.New("Bad host")
+	}
+	if user == "" {
+		return errors.New("Bad username")
+	}
+	if pass == "" {
+		return errors.New("Bad password")
+	}
+
+	return nil
+}
+
+func main() {
+	var flags struct {
+		host string
+		port int
+		user string
+		pass string
+	}
+	flag.StringVar(&flags.host, "host", "", "SMTP server to connect to")
+	flag.IntVar(&flags.port, "port", 587, "Port to connect to SMTP server on")
+	flag.StringVar(&flags.user, "user", "", "Username to authenticate with")
+	flag.StringVar(&flags.pass, "pass", "", "Password to authenticate with")
+	flag.Parse()
+
+	err := check(flags.host, flags.user, flags.pass)
+	if err != nil {
+		flag.Usage()
+		os.Exit(1)
+	}
+
+	bufin := bufio.NewReader(os.Stdin)
+
+	fmt.Printf("From: ")
+	from, err := bufin.ReadString('\n')
+	if err != nil {
+		fmt.Printf("Error: %v\n", err)
+		os.Exit(1)
+	}
+	from = strings.Trim(from, " \t\n\r")
+
+	var to []string
+	for {
+		fmt.Printf("To (Blank to finish): ")
+		tmp, err := bufin.ReadString('\n')
+		if err != nil {
+			fmt.Printf("Error: %v\n", err)
+			os.Exit(1)
+		}
+		tmp = strings.Trim(tmp, " \t\n\r")
+
+		if tmp == "" {
+			break
+		}
+
+		to = append(to, tmp)
+	}
+
+	var cc []string
+	for {
+		fmt.Printf("Cc (Blank to finish): ")
+		tmp, err := bufin.ReadString('\n')
+		if err != nil {
+			fmt.Printf("Error: %v\n", err)
+			os.Exit(1)
+		}
+		tmp = strings.Trim(tmp, " \t\n\r")
+
+		if tmp == "" {
+			break
+		}
+
+		cc = append(cc, tmp)
+	}
+
+	fmt.Printf("Subject: ")
+	subject, err := bufin.ReadString('\n')
+	if err != nil {
+		fmt.Printf("Error: %v\n", err)
+		os.Exit(1)
+	}
+	subject = strings.Trim(subject, " \t\n\r")
+
+	fmt.Printf("Content (Until EOF):\n")
+	content, err := ioutil.ReadAll(os.Stdin)
+	if err != nil {
+		fmt.Printf("Error: %v\n", err)
+		os.Exit(1)
+	}
+	content = bytes.Trim(content, " \t\n\r")
+
+	m := Message{
+		From:    from,
+		To:      to,
+		Cc:      cc,
+		Subject: subject,
+		Content: string(content),
+	}
+
+	fmt.Printf("\nSending message...\n")
+	err = m.Send(flags.host, flags.port, flags.user, flags.pass)
+	if err != nil {
+		fmt.Printf("Error: %v\n", err)
+		os.Exit(1)
+	}
+
+	fmt.Printf("Message sent.\n")
+}