1 // Copyright 2010 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
5 // The textproto package implements generic support for
6 // text-based request/response protocols in the style of
7 // HTTP, NNTP, and SMTP.
9 // The package provides:
11 // Error, which represents a numeric error response from
14 // Pipeline, to manage pipelined requests and responses
17 // Reader, to read numeric response code lines,
18 // key: value headers, lines wrapped with leading spaces
19 // on continuation lines, and whole text blocks ending
20 // with a dot on a line by itself.
22 // Writer, to write dot-encoded text blocks.
34 // An Error represents a numeric error response from a server.
40 func (e *Error) String() string {
41 return fmt.Sprintf("%03d %s", e.Code, e.Msg)
44 // A ProtocolError describes a protocol violation such
45 // as an invalid response or a hung-up connection.
46 type ProtocolError string
48 func (p ProtocolError) String() string {
52 // A Conn represents a textual network protocol connection.
53 // It consists of a Reader and Writer to manage I/O
54 // and a Pipeline to sequence concurrent requests on the connection.
55 // These embedded types carry methods with them;
56 // see the documentation of those types for details.
61 conn io.ReadWriteCloser
64 // NewConn returns a new Conn using conn for I/O.
65 func NewConn(conn io.ReadWriteCloser) *Conn {
67 Reader: Reader{R: bufio.NewReader(conn)},
68 Writer: Writer{W: bufio.NewWriter(conn)},
73 // Close closes the connection.
74 func (c *Conn) Close() os.Error {
78 // Dial connects to the given address on the given network using net.Dial
79 // and then returns a new Conn for the connection.
80 func Dial(network, addr string) (*Conn, os.Error) {
81 c, err := net.Dial(network, "", addr)
85 return NewConn(c), nil
88 // Cmd is a convenience method that sends a command after
89 // waiting its turn in the pipeline. The command text is the
90 // result of formatting format with args and appending \r\n.
91 // Cmd returns the id of the command, for use with StartResponse and EndResponse.
93 // For example, a client might run a HELP command that returns a dot-body
96 // id, err := c.Cmd("HELP")
101 // c.StartResponse(id)
102 // defer c.EndResponse(id)
104 // if _, _, err = c.ReadCodeLine(110); err != nil {
107 // text, err := c.ReadDotAll()
111 // return c.ReadCodeLine(250)
113 func (c *Conn) Cmd(format string, args ...interface{}) (id uint, err os.Error) {
116 err = c.PrintfLine(format, args...)