--- /dev/null
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package mail implements parsing of mail messages according to RFC 5322.
+package mail
+
+import (
+ "bufio"
+ "io"
+ "net/textproto"
+ "os"
+ "time"
+)
+
+// A Message represents a parsed mail message.
+type Message struct {
+ Header Header
+ Body io.Reader
+}
+
+// ReadMessage reads a message from r.
+// The headers are parsed, and the body of the message will be reading from r.
+func ReadMessage(r io.Reader) (msg *Message, err os.Error) {
+ tp := textproto.NewReader(bufio.NewReader(r))
+
+ hdr, err := tp.ReadMIMEHeader()
+ if err != nil {
+ return nil, err
+ }
+
+ return &Message{
+ Header: Header(hdr),
+ Body: tp.R,
+ }, nil
+}
+
+// Layouts suitable for passing to time.Parse.
+// These are tried in order.
+var dateLayouts []string
+
+func init() {
+ // Generate layouts based on RFC 5322, section 3.3.
+
+ dows := [...]string{"", "Mon, "} // day-of-week
+ days := [...]string{"2", "02"} // day = 1*2DIGIT
+ years := [...]string{"2006", "06"} // year = 4*DIGIT / 2*DIGIT
+ seconds := [...]string{":05", ""} // second
+ zones := [...]string{"-0700", "MST"} // zone = (("+" / "-") 4DIGIT) / "GMT" / ...
+
+ for _, dow := range dows {
+ for _, day := range days {
+ for _, year := range years {
+ for _, second := range seconds {
+ for _, zone := range zones {
+ s := dow + day + " Jan " + year + " 15:04" + second + " " + zone
+ dateLayouts = append(dateLayouts, s)
+ }
+ }
+ }
+ }
+ }
+}
+
+func parseDate(date string) (*time.Time, os.Error) {
+ for _, layout := range dateLayouts {
+ t, err := time.Parse(layout, date)
+ if err == nil {
+ return t, nil
+ }
+ }
+ return nil, os.ErrorString("mail: header could not be parsed")
+}
+
+// TODO(dsymonds): Parsers for more specific headers such as To, From, etc.
+
+// A Header represents the key-value pairs in a mail message header.
+type Header map[string][]string
+
+// Get gets the first value associated with the given key.
+// If there are no values associated with the key, Get returns "".
+func (h Header) Get(key string) string {
+ return textproto.MIMEHeader(h).Get(key)
+}
+
+var ErrHeaderNotPresent = os.ErrorString("mail: header not in message")
+
+// Date parses the Date header field.
+func (h Header) Date() (*time.Time, os.Error) {
+ hdr := h.Get("Date")
+ if hdr == "" {
+ return nil, ErrHeaderNotPresent
+ }
+ return parseDate(hdr)
+}
--- /dev/null
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package mail
+
+import (
+ "bytes"
+ "io/ioutil"
+ "reflect"
+ "testing"
+ "time"
+)
+
+var parseTests = []struct {
+ in string
+ header Header
+ body string
+}{
+ {
+ // RFC 5322, Appendix A.1.1
+ in: `From: John Doe <jdoe@machine.example>
+To: Mary Smith <mary@example.net>
+Subject: Saying Hello
+Date: Fri, 21 Nov 1997 09:55:06 -0600
+Message-ID: <1234@local.machine.example>
+
+This is a message just to say hello.
+So, "Hello".
+`,
+ header: Header{
+ "From": []string{"John Doe <jdoe@machine.example>"},
+ "To": []string{"Mary Smith <mary@example.net>"},
+ "Subject": []string{"Saying Hello"},
+ "Date": []string{"Fri, 21 Nov 1997 09:55:06 -0600"},
+ "Message-Id": []string{"<1234@local.machine.example>"},
+ },
+ body: "This is a message just to say hello.\nSo, \"Hello\".\n",
+ },
+}
+
+func TestParsing(t *testing.T) {
+ for i, test := range parseTests {
+ msg, err := ReadMessage(bytes.NewBuffer([]byte(test.in)))
+ if err != nil {
+ t.Errorf("test #%d: Failed parsing message: %v", i, err)
+ continue
+ }
+ if !headerEq(msg.Header, test.header) {
+ t.Errorf("test #%d: Incorrectly parsed message header.\nGot:\n%+v\nWant:\n%+v",
+ i, msg.Header, test.header)
+ }
+ body, err := ioutil.ReadAll(msg.Body)
+ if err != nil {
+ t.Errorf("test #%d: Failed reading body: %v", i, err)
+ continue
+ }
+ bodyStr := string(body)
+ if bodyStr != test.body {
+ t.Errorf("test #%d: Incorrectly parsed message body.\nGot:\n%+v\nWant:\n%+v",
+ i, bodyStr, test.body)
+ }
+ }
+}
+
+func headerEq(a, b Header) bool {
+ if len(a) != len(b) {
+ return false
+ }
+ for k, as := range a {
+ bs, ok := b[k]
+ if !ok {
+ return false
+ }
+ if !reflect.DeepEqual(as, bs) {
+ return false
+ }
+ }
+ return true
+}
+
+func TestDateParsing(t *testing.T) {
+ tests := []struct {
+ dateStr string
+ exp *time.Time
+ }{
+ // RFC 5322, Appendix A.1.1
+ {
+ "Fri, 21 Nov 1997 09:55:06 -0600",
+ &time.Time{
+ Year: 1997,
+ Month: 11,
+ Day: 21,
+ Hour: 9,
+ Minute: 55,
+ Second: 6,
+ Weekday: 5, // Fri
+ ZoneOffset: -6 * 60 * 60,
+ },
+ },
+ // RFC5322, Appendix A.6.2
+ // Obsolete date.
+ {
+ "21 Nov 97 09:55:06 GMT",
+ &time.Time{
+ Year: 1997,
+ Month: 11,
+ Day: 21,
+ Hour: 9,
+ Minute: 55,
+ Second: 6,
+ Zone: "GMT",
+ },
+ },
+ }
+ for _, test := range tests {
+ hdr := Header{
+ "Date": []string{test.dateStr},
+ }
+ date, err := hdr.Date()
+ if err != nil {
+ t.Errorf("Failed parsing %q: %v", test.dateStr, err)
+ continue
+ }
+ if !reflect.DeepEqual(date, test.exp) {
+ t.Errorf("Parse of %q: got %+v, want %+v", test.dateStr, date, test.exp)
+ }
+ }
+}