diff --git a/app/driver/readline.c b/app/driver/readline.c
index 78781a06..7d755d5d 100644
--- a/app/driver/readline.c
+++ b/app/driver/readline.c
@@ -11,15 +11,14 @@ extern UartDevice UartDev;
 
 #define uart_putc uart0_putc
 
-char ICACHE_FLASH_ATTR uart_getc(void){
-    char c = 0;
+bool ICACHE_FLASH_ATTR uart_getc(char *c){
     RcvMsgBuff *pRxBuff = &(UartDev.rcv_buff);
     if(pRxBuff->pWritePos == pRxBuff->pReadPos){   // empty
-        return 0;
+        return false;
     }
     // ETS_UART_INTR_DISABLE();
     ETS_INTR_LOCK();
-    c = (char)*(pRxBuff->pReadPos);
+    *c = (char)*(pRxBuff->pReadPos);
     if (pRxBuff->pReadPos == (pRxBuff->pRcvMsgBuff + RX_BUFF_SIZE)) {
         pRxBuff->pReadPos = pRxBuff->pRcvMsgBuff ; 
     } else {
@@ -27,7 +26,7 @@ char ICACHE_FLASH_ATTR uart_getc(void){
     }
     // ETS_UART_INTR_ENABLE();
     ETS_INTR_UNLOCK();
-    return c;
+    return true;
 }
 
 #if 0
@@ -43,13 +42,13 @@ start:
     os_memset(buffer, 0, length);
     while (1)
     {
-        while ((ch = uart_getc()) != 0)
+        while (uart_getc(&ch))
         {
             /* handle CR key */
             if (ch == '\r')
             {
                 char next;
-                if ((next = uart_getc()) != 0)
+                if (uart_getc(&next))
                     ch = next;
             }
             /* backspace key */
diff --git a/app/lua/lua.c b/app/lua/lua.c
index 24807a08..bd85ff4b 100644
--- a/app/lua/lua.c
+++ b/app/lua/lua.c
@@ -490,34 +490,6 @@ void ICACHE_FLASH_ATTR dojob(lua_Load *load){
   do{
     if(load->done == 1){
       l = c_strlen(b);
-#if 0
-      if(log_fd!=-1 && l>0)
-      {
-        if(l>=10 && (c_strstr(b,"log.stop()")) )
-        {
-          fs_close(log_fd);
-          log_fd = -1;
-          noparse = 0;
-          NODE_ERR( "log stopping.\n" );
-        }
-        if(log_fd!=-1){   // test again
-          rs = fs_write(log_fd, b, l);
-          if(rs!=l){
-            fs_close(log_fd);
-            log_fd = -1;
-          } else {
-            rs = fs_write(log_fd, "\r\n", 2);
-            if(rs!=2){
-              fs_close(log_fd);
-              log_fd = -1;
-            }
-          }
-        }
-        if(noparse){
-          break;
-        }
-      }
-#endif
       if (l > 0 && b[l-1] == '\n')  /* line ends with newline? */
         b[l-1] = '\0';  /* remove it */
       if (load->firstline && b[0] == '=')  /* first line starts with `=' ? */
@@ -613,86 +585,100 @@ void ICACHE_FLASH_ATTR update_key_led(){
 #endif
 extern bool uart_on_data_cb(const char *buf, size_t len);
 extern bool uart0_echo;
+extern bool run_input;
+extern uint16_t need_len;
+extern int16_t end_char;
 void ICACHE_FLASH_ATTR readline(lua_Load *load){
   // NODE_DBG("readline() is called.\n");
   update_key_led();
   char ch;
-  while ((ch = uart_getc()) != 0)
+  while (uart_getc(&ch))
   {
-    /* handle CR key */
-    if (ch == '\r')
+    if(run_input)
     {
-      char next;
-      if ((next = uart_getc()) != 0)
-        ch = next;
-    }
-    /* backspace key */
-    else if (ch == 0x7f || ch == 0x08)
-    {
-      if (load->line_position > 0)
+      /* handle CR key */
+      if (ch == '\r')
       {
-        if(uart0_echo) uart_putc(0x08);
-        if(uart0_echo) uart_putc(' ');
-        if(uart0_echo) uart_putc(0x08);
-        load->line_position--;
+        char next;
+        if (uart_getc(&next))
+          ch = next;
       }
-      load->line[load->line_position] = 0;
-      continue;
-    }
-    /* EOF(ctrl+d) */
-    else if (ch == 0x04)
-    {
-      if (load->line_position == 0)
-        // No input which makes lua interpreter close 
-        donejob(load);
-      else
+      /* backspace key */
+      else if (ch == 0x7f || ch == 0x08)
+      {
+        if (load->line_position > 0)
+        {
+          if(uart0_echo) uart_putc(0x08);
+          if(uart0_echo) uart_putc(' ');
+          if(uart0_echo) uart_putc(0x08);
+          load->line_position--;
+        }
+        load->line[load->line_position] = 0;
         continue;
-    }
-    /* end of line */
-    if (ch == '\r' || ch == '\n')
-    {
-      load->line[load->line_position] = 0;
-      if(uart0_echo) uart_putc('\n');
-      if(uart_on_data_cb(load->line, load->line_position)){
+      }
+      /* EOF(ctrl+d) */
+      else if (ch == 0x04)
+      {
+        if (load->line_position == 0)
+          // No input which makes lua interpreter close 
+          donejob(load);
+        else
+          continue;
+      }
+
+      /* end of line */
+      if (ch == '\r' || ch == '\n')
+      {
+        load->line[load->line_position] = 0;
+        if(uart0_echo) uart_putc('\n');
+        uart_on_data_cb(load->line, load->line_position);
+        if (load->line_position == 0)
+        {
+          /* Get a empty line, then go to get a new line */
+          c_puts(load->prmt);
+          os_timer_disarm(&readline_timer);
+          os_timer_setfn(&readline_timer, (os_timer_func_t *)readline, load);
+          os_timer_arm(&readline_timer, READLINE_INTERVAL, 0);   // no repeat
+        } else {
+          load->done = 1;
+          os_timer_disarm(&lua_timer);
+          os_timer_setfn(&lua_timer, (os_timer_func_t *)dojob, load);
+          os_timer_arm(&lua_timer, READLINE_INTERVAL, 0);   // no repeat
+        }
+      }
+
+      /* other control character or not an acsii character */
+      if (ch < 0x20 || ch >= 0x80)
+      {
+        continue;
+      }
+      /* echo */
+      if(uart0_echo) uart_putc(ch);
+
+          /* it's a large line, discard it */
+      if ( load->line_position + 1 >= load->len ){
         load->line_position = 0;
       }
-      if (load->line_position == 0)
-      {
-        /* Get a empty line, then go to get a new line */
-        c_puts(load->prmt);
-        os_timer_disarm(&readline_timer);
-        os_timer_setfn(&readline_timer, (os_timer_func_t *)readline, load);
-        os_timer_arm(&readline_timer, READLINE_INTERVAL, 0);   // no repeat
-      } else {
-        load->done = 1;
-        os_timer_disarm(&lua_timer);
-        os_timer_setfn(&lua_timer, (os_timer_func_t *)dojob, load);
-        os_timer_arm(&lua_timer, READLINE_INTERVAL, 0);   // no repeat
-      }
     }
-    /* other control character or not an acsii character */
-    if (ch < 0x20 || ch >= 0x80)
-    {
-      continue;
-    }
-    /* echo */
-    if(uart0_echo) uart_putc(ch);
+
     load->line[load->line_position] = ch;
-    ch = 0;
     load->line_position++;
 
-    /* it's a large line, discard it */
-    if (load->line_position >= load->len)
-      load->line_position = 0;
+    if(!run_input)
+    {
+      if( ((need_len!=0) && (load->line_position >= need_len)) || \
+        (load->line_position >= load->len) || \
+        ((end_char>=0) && ((unsigned char)ch==(unsigned char)end_char)) )
+      {
+        uart_on_data_cb(load->line, load->line_position);
+        load->line_position = 0;
+      }
+    }
+
+    ch = 0;
   }
   // if there is no input from user, repeat readline()
   os_timer_disarm(&readline_timer);
   os_timer_setfn(&readline_timer, (os_timer_func_t *)readline, load);
   os_timer_arm(&readline_timer, READLINE_INTERVAL, 0);   // no repeat
 }
-
-void ICACHE_FLASH_ATTR dogc(void){
-  if(globalL){
-    lua_gc(globalL, LUA_GCCOLLECT, 0);
-  }
-}
diff --git a/app/modules/uart.c b/app/modules/uart.c
index 98d3c5dd..99d811a8 100644
--- a/app/modules/uart.c
+++ b/app/modules/uart.c
@@ -12,7 +12,7 @@
 
 static lua_State *gL = NULL;
 static int uart_receive_rf = LUA_NOREF;
-static bool run_input = true;
+bool run_input = true;
 bool ICACHE_FLASH_ATTR uart_on_data_cb(const char *buf, size_t len){
   if(!buf || len==0)
     return false;
@@ -26,21 +26,46 @@ bool ICACHE_FLASH_ATTR uart_on_data_cb(const char *buf, size_t len){
   return !run_input;
 }
 
+uint16_t need_len = 0;
+int16_t end_char = -1;
 // Lua: uart.on("method", function, [run_input])
 static int ICACHE_FLASH_ATTR uart_on( lua_State* L )
 {
-  size_t sl;
+  size_t sl, el;
   int32_t run = 1;
-  const char *method = luaL_checklstring( L, 1, &sl );
+  uint8_t stack = 1;
+  const char *method = luaL_checklstring( L, stack, &sl );
+  stack++;
   if (method == NULL)
     return luaL_error( L, "wrong arg type" );
 
-  // luaL_checkanyfunction(L, 2);
-  if (lua_type(L, 2) == LUA_TFUNCTION || lua_type(L, 2) == LUA_TLIGHTFUNCTION){
-    if ( lua_isnumber(L, 3) ){
-      run = lua_tointeger(L, 3);
+  if( lua_type( L, stack ) == LUA_TNUMBER )
+  {
+    need_len = ( uint16_t )luaL_checkinteger( L, stack );
+    stack++;
+    end_char = -1;
+    if( need_len > 255 ){
+      need_len = 255;
+      return luaL_error( L, "wrong arg range" );
     }
-    lua_pushvalue(L, 2);  // copy argument (func) to the top of stack
+  }
+  else if(lua_isstring(L, stack))
+  {
+    const char *end = luaL_checklstring( L, stack, &el );
+    stack++;
+    if(el!=1){
+      return luaL_error( L, "wrong arg range" );
+    }
+    end_char = (int16_t)end[0];
+    need_len = 0;
+  }
+
+  // luaL_checkanyfunction(L, stack);
+  if (lua_type(L, stack) == LUA_TFUNCTION || lua_type(L, stack) == LUA_TLIGHTFUNCTION){
+    if ( lua_isnumber(L, stack+1) ){
+      run = lua_tointeger(L, stack+1);
+    }
+    lua_pushvalue(L, stack);  // copy argument (func) to the top of stack
   } else {
     lua_pushnil(L);
   }
diff --git a/examples/fragment.lua b/examples/fragment.lua
index 4acadc8c..7f02823e 100644
--- a/examples/fragment.lua
+++ b/examples/fragment.lua
@@ -303,3 +303,9 @@ sk=net.createConnection(net.TCP, 1) sk:on("receive", function(sck, c) print(c) e
 sk:on("connection", function(sck) sck:send("GET / HTTPS/1.1\r\nHost: www.google.com.hk\r\nConnection: keep-alive\r\nAccept: */*\r\n\r\n") end ) sk:connect(443,"173.194.72.199") 
 
 wifi.sta.setip({ip="192.168.18.119",netmask="255.255.255.0",gateway="192.168.18.1"})
+
+uart.on("data","\r",function(input) if input=="quit\r" then uart.on("data") else print(input) end end, 0)
+uart.on("data","\n",function(input) if input=="quit\n" then uart.on("data") else print(input) end end, 0)
+uart.on("data", 5 ,function(input) if input=="quit\r" then uart.on("data") else print(input) end end, 0)
+
+uart.on("data","\r",function(input) if input=="quit" then uart.on("data") else print(input) end end, 1)