1 files changed, 80 insertions, 0 deletions
diff --git a/scripts/mailing-list-member-retirement/main.go b/scripts/mailing-list-member-retirement/main.go
new file mode 100644
index 0000000..7ce7867
--- /dev/null
+++ b/scripts/mailing-list-member-retirement/main.go
@@ -0,0 +1,80 @@
+package main
+
+import (
+	"bufio"
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"strings"
+	"github.com/emersion/go-mbox"
+	"github.com/emersion/go-message/mail"
+	_ "github.com/emersion/go-message/charset"
+)
+
+// Prints the email addresses (one per line) of all senders by parsing an MBOX.
+
+func main() {
+	mboxNamePtr := flag.String("mbox", "test.mbox", "MBOX to read")
+	flag.Parse()
+	PrintAllMboxSenders(*mboxNamePtr)
+}
+
+func PrintAllMboxSenders(fileName string) {
+	f, err := os.Open(fileName)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer func() {
+		if err = f.Close(); err != nil {
+			log.Fatal(err)
+		}
+	}()
+	fr := bufio.NewReader(f)
+	mr := mbox.NewReader(fr)
+	for {
+		r, err := mr.NextMessage()
+		if err == io.EOF {
+			break
+		} else if err != nil {
+			log.Fatal(err)
+		}
+		PrintMessageSender(r)
+	}
+}
+
+func PrintMessageSender(r io.Reader) {
+	mr, err := mail.CreateReader(r)
+	if err != nil {
+		if err.Error() == "charset \"cp-850\": ianaindex: invalid encoding name" {
+			fmt.Fprintf(os.Stderr, "Ignored a mail due to an invalid charset\n")
+			return // TODO: Print message ID
+		}
+		log.Fatal(err)
+	}
+
+	addr, err := mr.Header.AddressList("From")
+	if err != nil {
+		if strings.Contains(err.Error(), "invalid utf-8 in quoted-string") {
+			addr := strings.TrimPrefix(err.Error(), "mail: missing word in phrase: mail: invalid utf-8 in quoted-string: ")
+			fmt.Fprintf(os.Stderr, "Ignored due to invalid UTF-8 encoding: %v\n", addr)
+			return
+		} else if err.Error() == "mail: missing @ in addr-spec" {
+			fmt.Fprintf(os.Stderr, "Ignored a sender due to missing @\n")
+			return // TODO: Print invalid address
+		} else if err.Error() == "mail: no angle-addr" {
+			fmt.Fprintf(os.Stderr, "Ignored a mail due to no angle-address\n")
+			return // TODO: Print message ID
+		}
+		log.Fatal(err)
+	} else if len(addr) != 1 {
+		if len(addr) == 0 {
+			fmt.Fprintf(os.Stderr, "Ignored a mail due to a missing sender\n")
+			return // TODO: Print message ID
+		}
+		fmt.Fprintf(os.Stderr, "A mail has an unexpected number of senders: %v\n", len(addr))
+		return // TODO: Print message ID
+	}
+	fmt.Println(addr[0].Address)
+}