From 208f889a4a4092d9fbfc943d8a23e0afc0a2a2f4 Mon Sep 17 00:00:00 2001
From: Yao Wei <mwei@lxde.org>
Date: Thu, 11 Sep 2014 21:24:51 +0800
Subject: [PATCH] add backspace functionality in shell

---
 sys/shell/shell.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/sys/shell/shell.c b/sys/shell/shell.c
index 49e42818f3..6cc07e9630 100644
--- a/sys/shell/shell.c
+++ b/sys/shell/shell.c
@@ -236,6 +236,18 @@ static int readline(shell_t *shell, char *buf, size_t size)
             shell->put_char('\n');
             return 0;
         }
+        else if (c == '\b') {
+            if (line_buf_ptr == buf) {
+                /* The line is empty. */
+                continue;
+            }
+
+            *--line_buf_ptr = '\0';
+            /* white-tape the character */
+            shell->put_char('\b');
+            shell->put_char(' ');
+            shell->put_char('\b');
+        }
         else {
             *line_buf_ptr++ = c;
             shell->put_char(c);