diff --git a/README.md b/README.md
index d7550c4..fe3d468 100644
--- a/README.md
+++ b/README.md
@@ -1,8 +1,8 @@
 # letter shell 3.x
 
-![version](https://img.shields.io/badge/version-3.1.0-brightgreen.svg)
+![version](https://img.shields.io/badge/version-3.1.1-brightgreen.svg)
 ![standard](https://img.shields.io/badge/standard-c99-brightgreen.svg)
-![build](https://img.shields.io/badge/build-2021.05.24-brightgreen.svg)
+![build](https://img.shields.io/badge/build-2021.06.27-brightgreen.svg)
 ![license](https://img.shields.io/badge/license-MIT-brightgreen.svg)
 
 一个功能强大的嵌入式shell
@@ -165,6 +165,7 @@
     | SHELL_PARAMETER_MAX_NUMBER  | shell命令参数最大数量          |
     | SHELL_HISTORY_MAX_NUMBER    | 历史命令记录数量               |
     | SHELL_DOUBLE_CLICK_TIME     | 双击间隔(ms)                   |
+    | SHELL_QUICK_HELP            | 快速帮助                       |
     | SHELL_MAX_NUMBER            | 管理的最大shell数量            |
     | SHELL_GET_TICK()            | 获取系统时间(ms)               |
     | SHELL_USING_LOCK            | 是否使用锁                     |
@@ -283,7 +284,7 @@ letter shell采取一个静态数组对定义的多个shell进行管理，shell
 
 ### 执行未导出函数
 
-letter shell支持通过函数地址直接执行函数，可以方便执行那些没有导出，但是有临时需要使用的函数，使用命令`exec [addr] [args]`执行，使用此功能需要开启`SHELL_EXEC_UNDEF_FUNC`宏，注意，由于直接操作函数地址执行，如果给进的地址有误，可能引起程序崩溃
+letter shell支持通过函数地址直接执行函数，可以方便执行那些没有导出，但是又临时需要使用的函数，使用命令`exec [addr] [args]`执行，使用此功能需要开启`SHELL_EXEC_UNDEF_FUNC`宏，注意，由于直接操作函数地址执行，如果给进的地址有误，可能引起程序崩溃
 
 函数的地址可以通过编译生成的文件查找，比如说对于keil，可以在`.map`文件中查找到每个函数的地址，对于keil，`.map`文件中的地址需要偏移一个字节，才可以成功执行，比如说`shellClear`函数地址为`0x08028620`，则通过`exec`执行应为`exec 0x08028621`
 
@@ -297,7 +298,7 @@ letter shell 3.x将可执行的函数命令定义，用户定义，按键定义
 
 letter shell 支持使用命令导出方式和命令表方式进行命令的添加，定义，通过宏```SHELL_USING_CMD_EXPORT```控制
 
-命令导出方式支持keil，IAR(未测试)以及GCC
+命令导出方式支持keil，IAR以及GCC
 
 1. 命令导出方式
 
diff --git a/demo/x86-gcc/shell_cfg.h b/demo/x86-gcc/shell_cfg.h
index 974f5bf..78a1860 100644
--- a/demo/x86-gcc/shell_cfg.h
+++ b/demo/x86-gcc/shell_cfg.h
@@ -13,6 +13,7 @@
 #define __SHELL_CFG_H__
 
 #include "stdlib.h"
+unsigned int userGetTick();
 
 /**
  * @brief 是否使用默认shell任务while循环，使能宏`SHELL_USING_TASK`后此宏有意义
@@ -101,6 +102,12 @@
  */
 #define     SHELL_DOUBLE_CLICK_TIME     200
 
+/**
+ * @brief 快速帮助
+ *        作用于双击tab的场景，当使能此宏时，双击tab不会对命令进行help补全，而是直接显示对应命令的帮助信息
+ */
+#define     SHELL_QUICK_HELP            1
+
 /**
  * @brief 管理的最大shell数量
  */
@@ -124,7 +131,7 @@
  *        定义此宏为获取系统Tick，如`HAL_GetTick()`
  * @note 此宏不定义时无法使用双击tab补全命令help，无法使用shell超时锁定
  */
-#define     SHELL_GET_TICK()            0
+#define     SHELL_GET_TICK()            userGetTick()
 
 /**
  * @brief 使用锁
diff --git a/demo/x86-gcc/shell_port.c b/demo/x86-gcc/shell_port.c
index 8b5e50f..f882298 100644
--- a/demo/x86-gcc/shell_port.c
+++ b/demo/x86-gcc/shell_port.c
@@ -18,6 +18,7 @@
 #include <unistd.h>
 #include <stddef.h>
 #include <string.h>
+#include <sys/time.h>
 
 Shell shell;
 char shellBuffer[512];
@@ -28,6 +29,18 @@ Log log = {
     .level = LOG_DEBUG
 };
 
+/**
+ * @brief 获取系统tick
+ * 
+ * @return unsigned int 系统tick
+ */
+unsigned int userGetTick()
+{
+    struct timeval tv;
+    gettimeofday(&tv, NULL);
+    return (tv.tv_sec * 1000 + tv.tv_usec / 1000) & 0x7FFFFFFF;
+}
+
 /**
  * @brief 日志写函数实现
  * 
@@ -73,8 +86,8 @@ unsigned short userShellRead(char *data, unsigned short len)
     {
         *data++ = getchar();
     }
-    system("stty icanon");
-    system("stty echo");
+    // system("stty icanon");
+    // system("stty echo");
     return len;
 }
 
@@ -142,8 +155,8 @@ void userShellInit(void)
     log.write = terminalLogWrite;
     logRegister(&log, &shell);
 
-    logDebug("hello world");
-    logHexDump(LOG_ALL_OBJ, LOG_DEBUG, (void *)&shell, sizeof(shell));
+    // logDebug("hello world");
+    // logHexDump(LOG_ALL_OBJ, LOG_DEBUG, (void *)&shell, sizeof(shell));
 }
 
 
diff --git a/extensions/shell_enhance/shell_passthrough.c b/extensions/shell_enhance/shell_passthrough.c
index f951c58..fec78a5 100644
--- a/extensions/shell_enhance/shell_passthrough.c
+++ b/extensions/shell_enhance/shell_passthrough.c
@@ -40,20 +40,21 @@ unsigned int shellPassthrough(Shell *shell, const char *prompt, ShellPassthrough
             {
                 if (data == '\r' || data == '\n')
                 {
-                    if (shell->parser.length == 0)
+                    shellWriteString(shell, "\r\n");
+                    if (shell->parser.length != 0)
                     {
-                        continue;
+                        shell->parser.buffer[shell->parser.length] = 0;
+                        handler(shell->parser.buffer, shell->parser.length);
+                        shell->parser.length = 0;
+                        shell->parser.cursor = 0;
                     }
-                    shellWriteString(shell, "\r\n");
-                    shell->parser.buffer[shell->parser.length] = 0;
-                    handler(shell->parser.buffer, shell->parser.length);
-                    shell->parser.length = 0;
-                    shell->parser.cursor = 0;
                     shellWriteString(shell, prompt);
                 }
                 else if (data == SHELL_PASSTHROUGH_EXIT_KEY)
                 {
                     shellWriteString(shell, "\r\n");
+                    shell->parser.length = 0;
+                    shell->parser.cursor = 0;
                     return -1;
                 }
                 else
diff --git a/src/shell.c b/src/shell.c
index a5daebc..507e8e1 100644
--- a/src/shell.c
+++ b/src/shell.c
@@ -158,6 +158,7 @@ ShellCommand* shellSeekCommand(Shell *shell,
                                const char *cmd,
                                ShellCommand *base,
                                unsigned short compareLength);
+static void shellWriteCommandHelp(Shell *shell, char *cmd);
 
 /**
  * @brief shell 初始化
@@ -168,18 +169,21 @@ void shellInit(Shell *shell, char *buffer, unsigned short size)
 {
     shell->parser.length = 0;
     shell->parser.cursor = 0;
-    shell->history.offset = 0;
-    shell->history.number = 0;
-    shell->history.record = 0;
     shell->info.user = NULL;
     shell->status.isChecked = 1;
 
     shell->parser.buffer = buffer;
     shell->parser.bufferSize = size / (SHELL_HISTORY_MAX_NUMBER + 1);
+    
+#if SHELL_HISTORY_MAX_NUMBER > 0
+    shell->history.offset = 0;
+    shell->history.number = 0;
+    shell->history.record = 0;
     for (short i = 0; i < SHELL_HISTORY_MAX_NUMBER; i++)
     {
         shell->history.item[i] = buffer + shell->parser.bufferSize * (i + 1);
     }
+#endif /** SHELL_HISTORY_MAX_NUMBER > 0 */
 
 #if SHELL_USING_CMD_EXPORT == 1
     #if defined(__CC_ARM) || (defined(__ARMCC_VERSION) && __ARMCC_VERSION >= 6000000)
@@ -1271,6 +1275,7 @@ static void shellWriteReturnValue(Shell *shell, int value)
 }
 
 
+#if SHELL_HISTORY_MAX_NUMBER > 0
 /**
  * @brief shell历史记录添加
  * 
@@ -1350,6 +1355,7 @@ static void shellHistory(Shell *shell, signed char dir)
     }
     
 }
+#endif /** SHELL_HISTORY_MAX_NUMBER > 0 */
 
 
 /**
@@ -1382,7 +1388,9 @@ void shellExec(Shell *shell)
 
     if (shell->status.isChecked)
     {
+    #if SHELL_HISTORY_MAX_NUMBER > 0
         shellHistoryAdd(shell);
+    #endif /** SHELL_HISTORY_MAX_NUMBER > 0 */
         shellParserParam(shell);
         shell->parser.length = shell->parser.cursor = 0;
         if (shell->parser.paramCount == 0)
@@ -1411,6 +1419,7 @@ void shellExec(Shell *shell)
 }
 
 
+#if SHELL_HISTORY_MAX_NUMBER > 0
 /**
  * @brief shell上方向键输入
  * 
@@ -1433,6 +1442,7 @@ void shellDown(Shell *shell)
     shellHistory(shell, -1);
 }
 SHELL_EXPORT_KEY(SHELL_CMD_PERMISSION(0), 0x1B5B4200, shellDown, down);
+#endif /** SHELL_HISTORY_MAX_NUMBER > 0 */
 
 
 /**
@@ -1543,6 +1553,12 @@ void shellTab(Shell *shell)
             && shell->status.tabFlag
             && SHELL_GET_TICK() - shell->info.activeTime < SHELL_DOUBLE_CLICK_TIME)
         {
+        #if SHELL_QUICK_HELP == 1
+            shellWriteString(shell, "\r\n");
+            shellWriteCommandHelp(shell, shell->parser.buffer);
+            shellWritePrompt(shell, 1);
+            shellWriteString(shell, shell->parser.buffer);
+        #else
             shellClearCommandLine(shell);
             for (short i = shell->parser.length; i >= 0; i--)
             {
@@ -1553,6 +1569,7 @@ void shellTab(Shell *shell)
             shell->parser.length += 5;
             shell->parser.cursor = shell->parser.length;
             shellWriteString(shell, shell->parser.buffer);
+        #endif
         }
         else
         {
@@ -1614,6 +1631,31 @@ SHELL_EXPORT_KEY(SHELL_CMD_PERMISSION(0)|SHELL_CMD_ENABLE_UNCHECKED,
 0x0D0A0000, shellEnter, enter);
 #endif
 
+/**
+ * @brief shell 写命令帮助信息
+ * 
+ * @param shell shell对象
+ * @param cmd 命令字符串
+ */
+static void shellWriteCommandHelp(Shell *shell, char *cmd)
+{
+    ShellCommand *command = shellSeekCommand(shell,
+                                             cmd,
+                                             shell->commandList.base,
+                                             0);
+    if (command)
+    {
+        shellWriteString(shell, shellText[SHELL_TEXT_HELP_HEADER]);
+        shellWriteString(shell, shellGetCommandName(command));
+        shellWriteString(shell, "\r\n");
+        shellWriteString(shell, shellGetCommandDesc(command));
+        shellWriteString(shell, "\r\n");
+    }
+    else
+    {
+        shellWriteString(shell, shellText[SHELL_TEXT_CMD_NOT_FOUND]);
+    }
+}
 
 /**
  * @brief shell help
@@ -1631,22 +1673,7 @@ void shellHelp(int argc, char *argv[])
     }
     else if (argc > 1)
     {
-        ShellCommand *command = shellSeekCommand(shell,
-                                                 argv[1],
-                                                 shell->commandList.base,
-                                                 0);
-        if (command)
-        {
-            shellWriteString(shell, shellText[SHELL_TEXT_HELP_HEADER]);
-            shellWriteString(shell, shellGetCommandName(command));
-            shellWriteString(shell, "\r\n");
-            shellWriteString(shell, shellGetCommandDesc(command));
-            shellWriteString(shell, "\r\n");
-        }
-        else
-        {
-            shellWriteString(shell, shellText[SHELL_TEXT_CMD_NOT_FOUND]);
-        }
+        shellWriteCommandHelp(shell, argv[1]);
     }
 }
 SHELL_EXPORT_CMD(
diff --git a/src/shell.h b/src/shell.h
index 5f2aa56..f05a5e3 100644
--- a/src/shell.h
+++ b/src/shell.h
@@ -14,7 +14,7 @@
 
 #include "shell_cfg.h"
 
-#define     SHELL_VERSION               "3.1.0"                 /**< 版本号 */
+#define     SHELL_VERSION               "3.1.1"                 /**< 版本号 */
 
 
 /**
@@ -341,6 +341,7 @@ typedef struct shell_def
         unsigned short paramCount;                              /**< 参数数量 */
         int keyValue;                                           /**< 输入按键键值 */
     } parser;
+#if SHELL_HISTORY_MAX_NUMBER > 0
     struct
     {
         char *item[SHELL_HISTORY_MAX_NUMBER];                   /**< 历史记录 */
@@ -348,6 +349,7 @@ typedef struct shell_def
         unsigned short record;                                  /**< 当前记录位置 */
         signed short offset;                                    /**< 当前历史记录偏移 */
     } history;
+#endif /** SHELL_HISTORY_MAX_NUMBER > 0 */
     struct
     {
         void *base;                                             /**< 命令表基址 */
diff --git a/src/shell_cfg.h b/src/shell_cfg.h
index 37cabaf..55e1393 100644
--- a/src/shell_cfg.h
+++ b/src/shell_cfg.h
@@ -100,6 +100,13 @@
  */
 #define     SHELL_DOUBLE_CLICK_TIME     200
 
+/**
+ * @brief 快速帮助
+ *        作用于双击tab的场景，当使能此宏时，双击tab不会对命令进行help补全，而是直接显示对应命令的帮助信息
+ */
+#define     SHELL_QUICK_HELP            1
+
+
 /**
  * @brief 管理的最大shell数量
  */