package main import ( "bufio" "code.google.com/p/go.crypto/ssh/terminal" "crypto/rsa" "fmt" "io" "net" "os" "strings" "sync" "unicode" ) type Auth struct { Nick string Key rsa.PublicKey } func (a *Auth) Kind() string { return "auth" } type ReadWriter struct { io.Reader io.Writer } type Client struct { key *rsa.PrivateKey host string port int nick string conn net.Conn done chan interface{} mu sync.Mutex prompt string line []rune prev *terminal.State } func (c *Client) dial() error { addr := fmt.Sprintf("%s:%d", c.host, c.port) c.info("dialing %s", addr) conn, err := net.Dial("tcp", addr) if err != nil { return fmt.Errorf("client unable to connect: %v", err) } c.info("connected to %s", addr) c.conn = conn c.prompt = fmt.Sprintf("%s> ", addr) return nil } func (c *Client) handshake() error { r := &Auth{Nick: c.nick, Key: c.key.PublicKey} c.info("authenticating as %s", c.nick) return c.sendRequest(r) } func (c *Client) sendRequest(r request) error { return writeRequest(c.conn, r) } func (c *Client) info(template string, args ...interface{}) { c.mu.Lock() defer c.mu.Unlock() c.trunc() fmt.Print("\033[90m# ") fmt.Printf(template, args...) if !strings.HasSuffix(template, "\n") { fmt.Print("\n") } fmt.Printf("\033[0m") c.renderLine() } func (c *Client) trunc() { fmt.Print("\033[1K") // clear to beginning of the line fmt.Print("\r") // move to beginning of the line } func (c *Client) err(template string, args ...interface{}) { c.mu.Lock() defer c.mu.Unlock() c.trunc() fmt.Print("\033[31m# ") fmt.Printf(template, args...) if !strings.HasSuffix(template, "\n") { fmt.Print("\n") } fmt.Printf("\033[0m") c.renderLine() } func (c *Client) run() { go c.term() if err := c.dial(); err != nil { exit(1, "%v", err) } defer c.conn.Close() if err := c.handshake(); err != nil { exit(1, "%v", err) } <-c.done if c.prev != nil { terminal.Restore(0, c.prev) } } func (c *Client) renderLine() { fmt.Printf("\033[1K") // clear to beginning of current line fmt.Printf("\r") // move to beginning of current line fmt.Printf("%s%s", c.prompt, string(c.line)) // print the line with prompt } func (c *Client) control(r rune) { switch r { case 3: // ctrl+c c.eof() case 4: // EOF c.eof() case 12: // ctrl+l c.clear() case 13: // enter c.enter() case 21: // ctrl+u c.clearLine() case 127: // backspace c.backspace() default: c.info("undefined control sequence: %v %d %c", r, r, r) } } func (c *Client) enter() { fmt.Print("\n") line := string(c.line) c.line = make([]rune, 0, 32) c.exec(line) } func (c *Client) exec(line string) { parts := strings.Split(line, " ") if len(parts) == 0 { c.renderLine() return } switch parts[0] { default: c.err("unrecognized client command: %s", parts[0]) } } func (c *Client) eof() { fmt.Print("\033[1K") // clear to beginning of current line fmt.Print("\r") // move to beginning of current line c.done <- 1 } func (c *Client) clear() { fmt.Print("\033[2J") // clear the screen fmt.Print("\033[0;0f") // move to 0, 0 c.renderLine() } func (c *Client) clearLine() { c.line = make([]rune, 0, 32) c.renderLine() } func (c *Client) backspace() { if len(c.line) == 0 { return } c.line = c.line[:len(c.line)-1] c.renderLine() } func (c *Client) term() { old, err := terminal.MakeRaw(0) if err != nil { panic(err) } c.prev = old defer close(c.done) in := bufio.NewReader(os.Stdin) for { r, _, err := in.ReadRune() switch err { case io.EOF: return case nil: default: c.err("error reading rune: %v", err) } if unicode.IsGraphic(r) { c.line = append(c.line, r) c.renderLine() } else { c.control(r) } } } func connect() { if !terminal.IsTerminal(0) { exit(1, "yeah, this only works from a TTY for now, sry.") } key, err := privateKey() if err != nil { exit(1, "unable to open private key file: %v", err) } client := &Client{ key: key, host: options.host, port: options.port, nick: options.nick, done: make(chan interface{}), line: make([]rune, 0, 32), } client.run() }