telnet_server: support C-p, C-n for moving through history

This modifies telnet server to allow using common readline combinations to
move up/down history, without the need to touch cursor keys.

Change-Id: Ib659075883e91794b44f391f7c29bbdfdd679d10
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Reviewed-on: http://openocd.zylin.com/1376
Tested-by: jenkins
Reviewed-by: Freddie Chopin <freddie.chopin@gmail.com>

diff --git a/src/server/telnet_server.c b/src/server/telnet_server.c
index ecdb2bfa247edcf37e1f30afc55305b8b7e8ec2a..090aa86fdee33b0961b3ad93d9ec66b211d7e39b 100644 (file)
--- a/src/server/telnet_server.c
+++ b/src/server/telnet_server.c
@@ -266,6 +266,39 @@ static void telnet_clear_line(struct connection *connection,
        t_con->line_cursor = 0;
 }
 
+static void telnet_history_go(struct connection *connection, int idx)
+{
+       struct telnet_connection *t_con = connection->priv;
+
+       if (t_con->history[idx]) {
+               telnet_clear_line(connection, t_con);
+               t_con->line_size = strlen(t_con->history[idx]);
+               t_con->line_cursor = t_con->line_size;
+               memcpy(t_con->line, t_con->history[idx], t_con->line_size);
+               telnet_write(connection, t_con->line, t_con->line_size);
+               t_con->current_history = idx;
+       }
+       t_con->state = TELNET_STATE_DATA;
+}
+
+static void telnet_history_up(struct connection *connection)
+{
+       struct telnet_connection *t_con = connection->priv;
+
+       int last_history = (t_con->current_history > 0) ?
+                               t_con->current_history - 1 :
+                               TELNET_LINE_HISTORY_SIZE-1;
+       telnet_history_go(connection, last_history);
+}
+
+static void telnet_history_down(struct connection *connection)
+{
+       struct telnet_connection *t_con = connection->priv;
+
+       int next_history = (t_con->current_history + 1) % TELNET_LINE_HISTORY_SIZE;
+       telnet_history_go(connection, next_history);
+}
+
 static int telnet_input(struct connection *connection)
 {
        int bytes_read;
@@ -441,7 +474,11 @@ static int telnet_input(struct connection *connection)
                                                        if (t_con->line_cursor < t_con->line_size)
                                                                telnet_write(connection, t_con->line + t_con->line_cursor++, 1);
                                                        t_con->state = TELNET_STATE_DATA;
-                                               } else
+                                               } else if (*buf_p == CTRL('P'))         /* cursor up */
+                                                       telnet_history_up(connection);
+                                               else if (*buf_p == CTRL('N'))           /* cursor down */
+                                                       telnet_history_down(connection);
+                                               else
                                                        LOG_DEBUG("unhandled nonprintable: %2.2x", *buf_p);
                                        }
                                }
@@ -486,28 +523,9 @@ static int telnet_input(struct connection *connection)
                                                                        t_con->line + t_con->line_cursor++, 1);
                                                t_con->state = TELNET_STATE_DATA;
                                        } else if (*buf_p == 'A') {     /* cursor up */
-                                               int last_history = (t_con->current_history > 0) ?
-                                                               t_con->current_history - 1 : TELNET_LINE_HISTORY_SIZE-1;
-                                               if (t_con->history[last_history]) {
-                                                       telnet_clear_line(connection, t_con);
-                                                       t_con->line_size = strlen(t_con->history[last_history]);
-                                                       t_con->line_cursor = t_con->line_size;
-                                                       memcpy(t_con->line, t_con->history[last_history], t_con->line_size);
-                                                       telnet_write(connection, t_con->line, t_con->line_size);
-                                                       t_con->current_history = last_history;
-                                               }
-                                               t_con->state = TELNET_STATE_DATA;
+                                               telnet_history_up(connection);
                                        } else if (*buf_p == 'B') {     /* cursor down */
-                                               int next_history = (t_con->current_history + 1) % TELNET_LINE_HISTORY_SIZE;
-                                               if (t_con->history[next_history]) {
-                                                       telnet_clear_line(connection, t_con);
-                                                       t_con->line_size = strlen(t_con->history[next_history]);
-                                                       t_con->line_cursor = t_con->line_size;
-                                                       memcpy(t_con->line, t_con->history[next_history], t_con->line_size);
-                                                       telnet_write(connection, t_con->line, t_con->line_size);
-                                                       t_con->current_history = next_history;
-                                               }
-                                               t_con->state = TELNET_STATE_DATA;
+                                               telnet_history_down(connection);
                                        } else if (*buf_p == '3')
                                                t_con->last_escape = *buf_p;
                                        else