Add initial width and height

main.go

@@ -95,15 +95,32 @@ func handleConn(conn net.Conn, config *ssh.ServerConfig) {
 func handleChannel(channel ssh.Channel, requests <-chan *ssh.Request) {
 	defer channel.Close()
 	var ptmx *os.File
+	var termWidth, termHeight uint32 = 15, 15
 	for req := range requests {
 		switch req.Type {
 		case "pty-req":
+			if len(req.Payload) >= 8 {
+				width := binary.BigEndian.Uint32(req.Payload[len(req.Payload)-8:])
+				height := binary.BigEndian.Uint32(req.Payload[len(req.Payload)-4:])
+				if width > 0 {
+					termWidth = width
+				}
+				if height > 0 {
+					termHeight = height
+				}
+			}
 			req.Reply(true, nil)
 		case "window-change":
+			width := binary.BigEndian.Uint32(req.Payload)
+			height := binary.BigEndian.Uint32(req.Payload[4:])
+			if width > 0 {
+				termWidth = width
+			}
+			if height > 0 {
+				termHeight = height
+			}
 			if ptmx != nil {
-				width := binary.BigEndian.Uint32(req.Payload)
-				height := binary.BigEndian.Uint32(req.Payload[4:])
-				pty.Setsize(ptmx, &pty.Winsize{Cols: uint16(width), Rows: uint16(height)})
+				pty.Setsize(ptmx, &pty.Winsize{Cols: uint16(termWidth), Rows: uint16(termHeight)})
 			}
 			req.Reply(true, nil)
 		case "shell":
@@ -121,6 +138,7 @@ func handleChannel(channel ssh.Channel, requests <-chan *ssh.Request) {
 				log.Println("PTY start error:", err)
 				return
 			}
+			pty.Setsize(ptmx, &pty.Winsize{Cols: uint16(termWidth), Rows: uint16(termHeight)})
 			go func() {
 				defer ptmx.Close()
 				go io.Copy(channel, ptmx)