diff --git a/examples/c/asyncdemo.c b/examples/c/asyncdemo.c
index 9e214e0966f7848e1ea158a50882fa8c4b4739ca..07e61b871ed2bd8e857861d169973f2ff6153a72 100644
--- a/examples/c/asyncdemo.c
+++ b/examples/c/asyncdemo.c
@@ -45,7 +45,7 @@ typedef struct {
 
 void taos_insert_call_back(void *param, TAOS_RES *tres, int code);
 void taos_select_call_back(void *param, TAOS_RES *tres, int code);
-void taos_error(TAOS *taos);
+void shellPrintError(TAOS *taos);
 
 static void queryDB(TAOS *taos, char *command) {
   int i;
@@ -102,7 +102,7 @@ int main(int argc, char *argv[])
 
   taos = taos_connect(argv[1], "root", "taosdata", NULL, 0);
   if (taos == NULL)
-    taos_error(taos);
+    shellPrintError(taos);
 
   printf("success to connect to server\n");
 
@@ -193,7 +193,7 @@ int main(int argc, char *argv[])
   return 0;
 }
 
-void taos_error(TAOS *con)
+void shellPrintError(TAOS *con)
 {
   fprintf(stderr, "TDengine error: %s\n", taos_errstr(con));
   taos_close(con);
diff --git a/tools/shell/inc/shellCommand.h b/tools/shell/inc/shellCommand.h
index 82a7cfbf8f338a3fc1b50a22d0c5a73c152f0b52..726264dd5cbad4b7b4424dec71210c7b6c699c1c 100644
--- a/tools/shell/inc/shellCommand.h
+++ b/tools/shell/inc/shellCommand.h
@@ -23,16 +23,15 @@
 #define UP    3
 #define DOWN  4
 
-typedef struct Command Command;
-struct Command {
-  char *   buffer;
-  char *   command;
+typedef struct {
+  char    *buffer;
+  char    *command;
   unsigned commandSize;
   unsigned bufferSize;
   unsigned cursorOffset;
   unsigned screenOffset;
   unsigned endOffset;
-};
+} Command;
 
 extern void backspaceChar(Command *cmd);
 extern void clearLineBefore(Command *cmd);
@@ -44,10 +43,10 @@ extern void positionCursorHome(Command *cmd);
 extern void positionCursorEnd(Command *cmd);
 extern void showOnScreen(Command *cmd);
 extern void updateBuffer(Command *cmd);
-extern int isReadyGo(Command *cmd);
+extern int  isReadyGo(Command *cmd);
 extern void resetCommand(Command *cmd, const char s[]);
 
-int countPrefixOnes(unsigned char c);
+int  countPrefixOnes(unsigned char c);
 void clearScreen(int ecmd_pos, int cursor_pos);
 void printChar(char c, int times);
 void positionCursor(int step, int direction);
diff --git a/tools/shell/inc/shellInt.h b/tools/shell/inc/shellInt.h
index fe142a4c7d336985f1dbf88faa5470d6bcaa85ca..3bdeed6e2ca0408150143bf9f236530fd09f90be 100644
--- a/tools/shell/inc/shellInt.h
+++ b/tools/shell/inc/shellInt.h
@@ -13,11 +13,10 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef _TD_SHELL_H_
-#define _TD_SHELL_H_
+#ifndef _TD_SHELL_INT_H_
+#define _TD_SHELL_INT_H_
 
 #include "os.h"
-
 #include "taos.h"
 #include "taosdef.h"
 
@@ -26,64 +25,65 @@
 #define HISTORY_FILE         ".taos_history"
 #define DEFAULT_RES_SHOW_NUM 100
 
-typedef struct SShellHistory {
-  char* hist[MAX_HISTORY_SIZE];
-  int   hstart;
-  int   hend;
+typedef struct {
+  char*   hist[MAX_HISTORY_SIZE];
+  int32_t hstart;
+  int32_t hend;
 } SShellHistory;
 
-typedef struct SShellArguments {
-  char* host;
-  char* password;
-  char* user;
-  char* auth;
-  char* database;
-  char* timezone;
-  bool  is_raw_time;
-  bool  is_use_passwd;
-  bool  dump_config;
-  char  file[TSDB_FILENAME_LEN];
-  char  dir[TSDB_FILENAME_LEN];
-  int   threadNum;
-  int   check;
-  bool  status;
-  bool  verbose;
-  char* commands;
-  int   abort;
-  int   port;
-  int   pktLen;
-  int   pktNum;
-  char* pktType;
-  char* netTestRole;
-} SShellArguments;
+typedef struct {
+  const char* host;
+  const char* password;
+  const char* user;
+  const char* auth;
+  const char* database;
+  const char* file;
+  const char* cfgdir;
+  const char* commands;
+  bool        is_gen_auth;
+  bool        is_raw_time;
+  bool        is_client;
+  bool        is_server;
+  bool        is_version;
+  bool        is_dump_config;
+  bool        is_check;
+  bool        is_startup;
+  bool        is_help;
+  uint16_t    port;
+  int32_t     pktLen;
+  int32_t     pktNum;
+  int32_t     abort;
+} SShellArgs;
+
+typedef struct {
+  SShellArgs    args;
+  SShellHistory history;
+  TAOS*         conn;
+  int64_t       result;
+} SShellObj;
+
+int32_t shellParseArgs(int32_t argc, char* argv[]);
+int32_t shellInit();
+void    shellCleanup(void* arg);
+void    shellExit();
+
+void*   shellThreadLoop(void* arg);
+void    shellPrintError(TAOS_RES* tres, int64_t st);
+int32_t shellRegexMatch(const char* s, const char* reg, int32_t cflags);
+void    shellGetGrantInfo();
+void    shellReadHistory();
+void    shellWriteHistory();
+void    shellHistoryPath(char* history);
 
-/**************** Function declarations ****************/
-extern void shellParseArgument(int argc, char* argv[], SShellArguments* arguments);
-extern TAOS* shellInit(SShellArguments* args);
-extern void* shellLoopQuery(void* arg);
-extern void taos_error(TAOS_RES* tres, int64_t st);
-extern int regex_match(const char* s, const char* reg, int cflags);
-int32_t shellReadCommand(TAOS* con, char command[]);
-int32_t shellRunCommand(TAOS* con, char* command);
-void shellRunCommandOnServer(TAOS* con, char command[]);
-void read_history();
-void write_history();
-void source_file(TAOS* con, char* fptr);
-void source_dir(TAOS* con, SShellArguments* args);
-void get_history_path(char* history);
-void shellCheck(TAOS* con, SShellArguments* args);
-void cleanup_handler(void* arg);
-void exitShell();
-int shellDumpResult(TAOS_RES* con, char* fname, int* error_no, bool printMode);
-void shellGetGrantInfo(void *con);
-int isCommentLine(char *line);
+int32_t shellReadCommand(char command[]);
+int32_t shellRunCommand(char* command);
+void    shellRunCommandImp(char command[]);
+void    shellSourceFile(TAOS* con, char* fptr);
+int32_t shellDumpResult(TAOS_RES* con, char* fname, int32_t* error_no, bool printMode);
 
-/**************** Global variable declarations ****************/
-extern char           PROMPT_HEADER[];
-extern char           CONTINUE_PROMPT[];
-extern int            prompt_size;
-extern SShellHistory  history;
-extern SShellArguments args;
-extern int64_t         result;
+extern char      PROMPT_HEADER[];
+extern char      CONTINUE_PROMPT[];
+extern int32_t   prompt_size;
+extern SShellObj shell;
 
-#endif
+#endif /*_TD_SHELL_INT_H_*/
diff --git a/tools/shell/inc/syncMsg.h b/tools/shell/inc/syncMsg.h
deleted file mode 100644
index 85ac9c78affa5282d5ca703caffc1bc5c24461bb..0000000000000000000000000000000000000000
--- a/tools/shell/inc/syncMsg.h
+++ /dev/null
@@ -1,141 +0,0 @@
-/*
- * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
- *
- * This program is free software: you can use, redistribute, and/or modify
- * it under the terms of the GNU Affero General Public License, version 3
- * or later ("AGPL"), as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#ifndef TDENGINE_SYNC_MSG_H
-#define TDENGINE_SYNC_MSG_H
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-#include "tsync.h"
-
-typedef enum {
-  TAOS_SMSG_START         = 0,
-  TAOS_SMSG_SYNC_DATA     = 1,
-  TAOS_SMSG_SYNC_DATA_RSP = 2,
-  TAOS_SMSG_SYNC_FWD      = 3,
-  TAOS_SMSG_SYNC_FWD_RSP  = 4,
-  TAOS_SMSG_SYNC_REQ      = 5,
-  TAOS_SMSG_SYNC_REQ_RSP  = 6,
-  TAOS_SMSG_SYNC_MUST     = 7,
-  TAOS_SMSG_SYNC_MUST_RSP = 8,
-  TAOS_SMSG_STATUS        = 9,
-  TAOS_SMSG_STATUS_RSP    = 10,
-  TAOS_SMSG_SETUP         = 11,
-  TAOS_SMSG_SETUP_RSP     = 12,
-  TAOS_SMSG_SYNC_FILE     = 13,
-  TAOS_SMSG_SYNC_FILE_RSP = 14,
-  TAOS_SMSG_TEST          = 15,
-  TAOS_SMSG_END           = 16
-} ESyncMsgType;
-
-typedef enum {
-  SYNC_STATUS_BROADCAST,
-  SYNC_STATUS_BROADCAST_RSP,
-  SYNC_STATUS_SETUP_CONN,
-  SYNC_STATUS_SETUP_CONN_RSP,
-  SYNC_STATUS_EXCHANGE_DATA,
-  SYNC_STATUS_EXCHANGE_DATA_RSP,
-  SYNC_STATUS_CHECK_ROLE,
-  SYNC_STATUS_CHECK_ROLE_RSP
-} ESyncStatusType;
-
-#pragma pack(push, 1)
-
-typedef struct {
-  int8_t   type;       // msg type
-  int8_t   protocol;   // protocol version
-  uint16_t signature;  // fixed value
-  int32_t  code;       //
-  int32_t  cId;        // cluster Id
-  int32_t  vgId;       // vg ID
-  int32_t  len;        // content length, does not include head
-  uint32_t cksum;
-} SSyncHead;
-
-typedef struct {
-  SSyncHead head;
-  uint16_t  port;
-  uint16_t  tranId;
-  int32_t   sourceId;  // only for arbitrator
-  char      fqdn[TSDB_FQDN_LEN];
-} SSyncMsg;
-
-typedef struct {
-  SSyncHead head;
-  int8_t    sync;
-  int8_t    reserved;
-  uint16_t  tranId;
-  int8_t    reserverd[4];
-} SSyncRsp;
-
-typedef struct {
-  int8_t    role;
-  uint64_t  version;
-} SPeerStatus;
-
-typedef struct {
-  SSyncHead   head;
-  int8_t      role;
-  int8_t      ack;
-  int8_t      type;
-  int8_t      reserved[3];
-  uint16_t    tranId;
-  uint64_t    version;
-  SPeerStatus peersStatus[TAOS_SYNC_MAX_REPLICA];
-} SPeersStatus;
-
-typedef struct {
-  SSyncHead head;
-  uint64_t  fversion;
-} SFileVersion;
-
-typedef struct {
-  SSyncHead head;
-  int8_t    ack;
-} SFileAck;
-
-typedef struct {
-  SSyncHead head;
-  uint64_t  version;
-  int32_t   code;
-} SFwdRsp;
-
-#pragma pack(pop)
-
-#define SYNC_PROTOCOL_VERSION 1
-#define SYNC_SIGNATURE ((uint16_t)(0xCDEF))
-
-extern char *statusType[];
-
-uint16_t syncGenTranId();
-int32_t  syncCheckHead(SSyncHead *pHead);
-
-void syncBuildSyncFwdMsg(SSyncHead *pHead, int32_t vgId, int32_t len);
-void syncBuildSyncFwdRsp(SFwdRsp *pMsg, int32_t vgId, uint64_t version, int32_t code);
-void syncBuildSyncReqMsg(SSyncMsg *pMsg, int32_t vgId);
-void syncBuildSyncDataMsg(SSyncMsg *pMsg, int32_t vgId);
-void syncBuildSyncSetupMsg(SSyncMsg *pMsg, int32_t vgId);
-void syncBuildPeersStatus(SPeersStatus *pMsg, int32_t vgId);
-void syncBuildSyncTestMsg(SSyncMsg *pMsg, int32_t vgId);
-
-void syncBuildFileAck(SFileAck *pMsg, int32_t vgId);
-void syncBuildFileVersion(SFileVersion *pMsg, int32_t vgId);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif  // TDENGINE_VNODEPEER_H
diff --git a/tools/shell/inc/tsync.h b/tools/shell/inc/tsync.h
deleted file mode 100644
index d1b68e3f5a1e27b63dd08a4d1d4862c7b1e68179..0000000000000000000000000000000000000000
--- a/tools/shell/inc/tsync.h
+++ /dev/null
@@ -1,127 +0,0 @@
-/*
- * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
- *
- * This program is free software: you can use, redistribute, and/or modify
- * it under the terms of the GNU Affero General Public License, version 3
- * or later ("AGPL"), as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#ifndef TDENGINE_SYNC_H
-#define TDENGINE_SYNC_H
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#define TAOS_SYNC_MAX_REPLICA 5
-#define TAOS_SYNC_MAX_INDEX   0x7FFFFFFF
-
-typedef enum {
-  TAOS_SYNC_ROLE_OFFLINE  = 0,
-  TAOS_SYNC_ROLE_UNSYNCED = 1,
-  TAOS_SYNC_ROLE_SYNCING  = 2,
-  TAOS_SYNC_ROLE_SLAVE    = 3,
-  TAOS_SYNC_ROLE_MASTER   = 4
-} ESyncRole;
-
-typedef enum {
-  TAOS_SYNC_STATUS_INIT  = 0,
-  TAOS_SYNC_STATUS_START = 1,
-  TAOS_SYNC_STATUS_FILE  = 2,
-  TAOS_SYNC_STATUS_CACHE = 3
-} ESyncStatus;
-
-typedef struct {
-  uint32_t  nodeId;    // node ID assigned by TDengine
-  uint16_t  nodePort;  // node sync Port
-  char      nodeFqdn[TSDB_FQDN_LEN]; // node FQDN  
-} SNodeInfo;
-
-typedef struct {
-  int8_t     quorum;    // number of confirms required, >=1 
-  int8_t     replica;   // number of replications, >=1
-  SNodeInfo  nodeInfo[TAOS_SYNC_MAX_REPLICA];
-} SSyncCfg;
-
-typedef struct {
-  int32_t  selfIndex;
-  uint32_t nodeId[TAOS_SYNC_MAX_REPLICA];
-  int32_t  role[TAOS_SYNC_MAX_REPLICA];
-} SNodesRole;
-
-// get the wal file from index or after
-// return value, -1: error, 1:more wal files, 0:last WAL. if name[0]==0, no WAL file
-typedef int32_t  (*FGetWalInfo)(int32_t vgId, char *fileName, int64_t *fileId); 
- 
-// when a forward pkt is received, call this to handle data
-typedef int32_t  (*FWriteToCache)(int32_t vgId, void *pHead, int32_t qtype, void *pMsg);
-
-// when forward is confirmed by peer, master call this API to notify app
-typedef void     (*FConfirmForward)(int32_t vgId, void *mhandle, int32_t code);
-
-// when role is changed, call this to notify app
-typedef void     (*FNotifyRole)(int32_t vgId, int8_t role);
-
-// if a number of retrieving data failed, call this to start flow control 
-typedef void     (*FNotifyFlowCtrl)(int32_t vgId, int32_t level);
-
-// when data file is synced successfully, notity app
-typedef void     (*FStartSyncFile)(int32_t vgId);
-typedef void     (*FStopSyncFile)(int32_t vgId, uint64_t fversion);
-
-// get file version
-typedef int32_t  (*FGetVersion)(int32_t vgId, uint64_t *fver, uint64_t *vver);
-
-typedef int32_t  (*FSendFile)(void *tsdb, SOCKET socketFd);
-typedef int32_t  (*FRecvFile)(void *tsdb, SOCKET socketFd);
-
-typedef struct {
-  int32_t  vgId;       // vgroup ID
-  uint64_t version;    // initial version
-  SSyncCfg syncCfg;    // configuration from mgmt
-  char     path[TSDB_FILENAME_LEN];  // path to the file
-  void *   pTsdb;
-  FGetWalInfo       getWalInfoFp;
-  FWriteToCache     writeToCacheFp;
-  FConfirmForward   confirmForward;
-  FNotifyRole       notifyRoleFp;
-  FNotifyFlowCtrl   notifyFlowCtrlFp;
-  FStartSyncFile    startSyncFileFp;
-  FStopSyncFile     stopSyncFileFp;
-  FGetVersion       getVersionFp;
-  FSendFile         sendFileFp;
-  FRecvFile         recvFileFp;
-} SSyncInfo;
-
-typedef void *tsync_h;
-
-int32_t syncInit();
-void    syncCleanUp();
-
-int64_t syncStart(const SSyncInfo *);
-void    syncStop(int64_t rid);
-int32_t syncReconfig(int64_t rid, const SSyncCfg *);
-int32_t syncForwardToPeer(int64_t rid, void *pHead, void *mhandle, int32_t qtype, bool force);
-void    syncConfirmForward(int64_t rid, uint64_t version, int32_t code, bool force);
-void    syncRecover(int64_t rid);  // recover from other nodes:
-int32_t syncGetNodesRole(int64_t rid, SNodesRole *);
-
-extern char *syncRole[];
-
-//global configurable parameters
-extern int32_t  sDebugFlag;
-extern char     tsArbitrator[];
-extern uint16_t tsSyncPort;
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif  // TDENGINE_SYNC_H
diff --git a/tools/shell/src/backup/shellCheck.c b/tools/shell/src/backup/shellCheck.c
deleted file mode 100644
index 9e23e9d02663c6b4f8e34f78c701033c749b054d..0000000000000000000000000000000000000000
--- a/tools/shell/src/backup/shellCheck.c
+++ /dev/null
@@ -1,202 +0,0 @@
-/*
- * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
- *
- * This program is free software: you can use, redistribute, and/or modify
- * it under the terms of the GNU Affero General Public License, version 3
- * or later ("AGPL"), as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#define _GNU_SOURCE
-#define _XOPEN_SOURCE
-#define _DEFAULT_SOURCE
-
-#include "os.h"
-#include "shellInt.h"
-#include "shellCommand.h"
-#include "tglobal.h"
-#include "tutil.h"
-
-#define SHELL_SQL_LEN 1024
-static int32_t tbNum = 0;
-static int32_t tbMallocNum = 0;
-static char ** tbNames = NULL;
-static int32_t checkedNum = 0;
-static int32_t errorNum = 0;
-
-typedef struct {
-  TdThread threadID;
-  int       threadIndex;
-  int       totalThreads;
-  void *    taos;
-  char *    db;
-} ShellThreadObj;
-
-static int32_t shellUseDb(TAOS *con, char *db) {
-  if (db == NULL) {
-    fprintf(stdout, "no dbname input\n");
-    return -1;
-  }
-
-  char sql[SHELL_SQL_LEN] = {0};
-  snprintf(sql, SHELL_SQL_LEN, "use %s", db);
-
-  TAOS_RES *pSql = taos_query(con, sql);
-  int32_t   code = taos_errno(pSql);
-  if (code != 0) {
-    fprintf(stdout, "failed to execute sql:%s since %s", sql, taos_errstr(pSql));
-  }
-
-  taos_free_result(pSql);
-  return code;
-}
-
-static int32_t shellShowTables(TAOS *con, char *db) {
-  char sql[SHELL_SQL_LEN] = {0};
-  snprintf(sql, SHELL_SQL_LEN, "show %s.tables", db);
-
-  TAOS_RES *pSql = taos_query(con, sql);
-  int32_t   code = taos_errno(pSql);
-
-  if (code != 0) {
-    fprintf(stdout, "failed to execute sql:%s since %s\n", sql, taos_errstr(pSql));
-  } else {
-    TAOS_ROW row;
-    while ((row = taos_fetch_row(pSql))) {
-      int32_t tbIndex = tbNum++;
-      if (tbMallocNum < tbNum) {
-        tbMallocNum = (tbMallocNum * 2 + 1);
-        char** tbNames1 = taosMemoryRealloc(tbNames, tbMallocNum * sizeof(char *));
-        if (tbNames1 == NULL) {
-          fprintf(stdout, "failed to malloc tablenames, num:%d\n", tbMallocNum);
-          code = TSDB_CODE_TSC_OUT_OF_MEMORY;
-          break;
-        }
-        tbNames = tbNames1;
-      }
-
-      tbNames[tbIndex] = taosMemoryMalloc(TSDB_TABLE_NAME_LEN);
-      strncpy(tbNames[tbIndex], (const char *)row[0], TSDB_TABLE_NAME_LEN);
-      if (tbIndex % 100000 == 0 && tbIndex != 0) {
-        fprintf(stdout, "%d tablenames fetched\n", tbIndex);
-      }
-    }
-  }
-
-  taos_free_result(pSql);
-
-  fprintf(stdout, "total %d tablenames fetched, over\n", tbNum);
-  return code;
-}
-
-static void shellFreeTbnames() {
-  for (int32_t i = 0; i < tbNum; ++i) {
-    taosMemoryFree(tbNames[i]);
-  }
-  taosMemoryFree(tbNames);
-}
-
-static void *shellCheckThreadFp(void *arg) {
-  ShellThreadObj *pThread = (ShellThreadObj *)arg;
-
-  setThreadName("shellCheckThrd");
-
-  int32_t interval = tbNum / pThread->totalThreads + 1;
-  int32_t start = pThread->threadIndex * interval;
-  int32_t end = (pThread->threadIndex + 1) * interval;
-
-  if (end > tbNum) end = tbNum + 1;
-
-  char file[32] = {0};
-  snprintf(file, 32, "tb%d.txt", pThread->threadIndex);
-
-  TdFilePtr pFile = taosOpenFile(file, TD_FILE_CREATE | TD_FILE_WRITE | TD_FILE_TRUNC);
-  if (!fp) {
-    fprintf(stdout, "failed to open %s, reason:%s", file, strerror(errno));
-    return NULL;
-  }
-
-  char sql[SHELL_SQL_LEN];
-  for (int32_t t = start; t < end; ++t) {
-    char *tbname = tbNames[t];
-    if (tbname == NULL) break;
-
-    snprintf(sql, SHELL_SQL_LEN, "select * from %s limit 1", tbname);
-
-    TAOS_RES *pSql = taos_query(pThread->taos, sql);
-    int32_t   code = taos_errno(pSql);
-    if (code != 0) {
-      int32_t len = snprintf(sql, SHELL_SQL_LEN, "drop table %s.%s;\n", pThread->db, tbname);
-      taosWriteFile(pFile, sql, len);
-      atomic_add_fetch_32(&errorNum, 1);
-    }
-
-    int32_t cnum = atomic_add_fetch_32(&checkedNum, 1);
-    if (cnum % 5000 == 0 && cnum != 0) {
-      fprintf(stdout, "%d tables checked\n", cnum);
-    }
-
-    taos_free_result(pSql);
-  }
-
-  taosFsync(pFile);
-  taosCloseFile(&pFile);
-
-  return NULL;
-}
-
-static void shellRunCheckThreads(TAOS *con, SShellArguments *_args) {
-  TdThreadAttr  thattr;
-  ShellThreadObj *threadObj = (ShellThreadObj *)taosMemoryCalloc(_args->threadNum, sizeof(ShellThreadObj));
-  for (int t = 0; t < _args->threadNum; ++t) {
-    ShellThreadObj *pThread = threadObj + t;
-    pThread->threadIndex = t;
-    pThread->totalThreads = _args->threadNum;
-    pThread->taos = con;
-    pThread->db = _args->database;
-
-    taosThreadAttrInit(&thattr);
-    taosThreadAttrSetDetachState(&thattr, PTHREAD_CREATE_JOINABLE);
-
-    if (taosThreadCreate(&(pThread->threadID), &thattr, shellCheckThreadFp, (void *)pThread) != 0) {
-      fprintf(stderr, "ERROR: thread:%d failed to start\n", pThread->threadIndex);
-      exit(0);
-    }
-  }
-
-  for (int t = 0; t < _args->threadNum; ++t) {
-    taosThreadJoin(threadObj[t].threadID, NULL);
-  }
-
-  for (int t = 0; t < _args->threadNum; ++t) {
-    taos_close(threadObj[t].taos);
-  }
-  taosMemoryFree(threadObj);
-}
-
-void shellCheck(TAOS *con, SShellArguments *_args) {
-  int64_t start = taosGetTimestampMs();
-
-  if (shellUseDb(con, _args->database) != 0) {
-    shellFreeTbnames();
-    return;
-  }
-
-  if (shellShowTables(con, _args->database) != 0) {
-    shellFreeTbnames();
-    return;
-  }
-
-  fprintf(stdout, "total %d tables will be checked by %d threads\n", tbNum, _args->threadNum);
-  shellRunCheckThreads(con, _args);
-
-  int64_t end = taosGetTimestampMs();
-  fprintf(stdout, "total %d tables checked, failed:%d, time spent %.2f seconds\n", checkedNum, errorNum,
-          (end - start) / 1000.0);
-}
diff --git a/tools/shell/src/backup/shellDarwin.c b/tools/shell/src/backup/shellDarwin.c
index d9807409f7c8e7cca97a41dfffeefe938da6ae1f..9bae306a7017140b14cc5c5c5c447a2809ddc94c 100644
--- a/tools/shell/src/backup/shellDarwin.c
+++ b/tools/shell/src/backup/shellDarwin.c
@@ -67,7 +67,7 @@ char      DARWINCLIENT_VERSION[] = "Welcome to the TDengine shell from %s, Clien
                              "Copyright (c) 2020 by TAOS Data, Inc. All rights reserved.\n\n";
 char g_password[SHELL_MAX_PASSWORD_LEN];
 
-void shellParseArgument(int argc, char *argv[], SShellArguments *arguments) {
+void shellParseArgs(int argc, char *argv[], SShellArgs *arguments) {
   wordexp_t full_path;
   for (int i = 1; i < argc; i++) {
     // for host
@@ -238,8 +238,8 @@ int32_t shellReadCommand(TAOS *con, char *command) {
           printf("\n");
           taos_close(con);
           // write the history
-          write_history();
-          exitShell();
+          shellWriteHistory();
+          shellExit();
           break;
         case 5:  // ctrl E
           positionCursorEnd(&cmd);
@@ -355,7 +355,7 @@ int32_t shellReadCommand(TAOS *con, char *command) {
   return 0;
 }
 
-void *shellLoopQuery(void *arg) {
+void *shellThreadLoop(void *arg) {
   if (indicator) {
     getOldTerminalMode();
     indicator = 0;
@@ -363,9 +363,9 @@ void *shellLoopQuery(void *arg) {
 
   TAOS *con = (TAOS *)arg;
 
-  setThreadName("shellLoopQuery");
+  setThreadName("shellThreadLoop");
 
-  taosThreadCleanupPush(cleanup_handler, NULL);
+  taosThreadCleanupPush(shellCleanup, NULL);
 
     char *command = taosMemoryMalloc(MAX_COMMAND_SIZE);
     if (command == NULL){
@@ -387,14 +387,14 @@ void *shellLoopQuery(void *arg) {
     } while (shellRunCommand(con, command) == 0);
 
   taosMemoryFreeClear(command);
-  exitShell();
+  shellExit();
 
   taosThreadCleanupPop(1);
 
   return NULL;
 }
 
-void get_history_path(char *history) { sprintf(history, "%s/%s", getpwuid(getuid())->pw_dir, HISTORY_FILE); }
+void shellHistoryPath(char *history) { sprintf(history, "%s/%s", getpwuid(getuid())->pw_dir, HISTORY_FILE); }
 
 void clearScreen(int ecmd_pos, int cursor_pos) {
   struct winsize w;
@@ -490,9 +490,9 @@ void showOnScreen(Command *cmd) {
   fflush(stdout);
 }
 
-void cleanup_handler(void *arg) { resetTerminalMode(); }
+void shellCleanup(void *arg) { resetTerminalMode(); }
 
-void exitShell() {
+void shellExit() {
   resetTerminalMode();
   exit(EXIT_SUCCESS);
 }
diff --git a/tools/shell/src/backup/shellImport.c b/tools/shell/src/backup/shellImport.c
deleted file mode 100644
index 2eeee616b4e39efd16af9dfe5ed6cfa9c54176b9..0000000000000000000000000000000000000000
--- a/tools/shell/src/backup/shellImport.c
+++ /dev/null
@@ -1,279 +0,0 @@
-/*
- * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
- *
- * This program is free software: you can use, redistribute, and/or modify
- * it under the terms of the GNU Affero General Public License, version 3
- * or later ("AGPL"), as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#define _GNU_SOURCE
-#define _XOPEN_SOURCE
-#define _DEFAULT_SOURCE
-
-#include "os.h"
-#include "shellInt.h"
-#include "shellCommand.h"
-#include "tglobal.h"
-#include "tutil.h"
-
-static char **shellSQLFiles = NULL;
-static int32_t shellSQLFileNum = 0;
-static char shellTablesSQLFile[TSDB_FILENAME_LEN] = {0};
-
-typedef struct {
-  TdThread threadID;
-  int       threadIndex;
-  int       totalThreads;
-  void     *taos;
-} ShellThreadObj;
-
-static int shellGetFilesNum(const char *directoryName, const char *prefix)
-{
-  char cmd[1024] = { 0 };
-  sprintf(cmd, "ls %s/*.%s | wc -l ", directoryName, prefix);
-
-  char buf[1024] = { 0 };
-  if (taosSystem(cmd, buf, sizeof(buf)) < 0) {
-    fprintf(stderr, "ERROR: failed to execute:%s, error:%s\n", cmd, strerror(errno));
-    exit(0);
-  }
-
-  int fileNum = 0;
-  if (sscanf(buf, "%d", &fileNum) != 1) {
-    fprintf(stderr, "ERROR: failed to execute:%s, parse result error\n", cmd);
-    exit(0);
-  }
-
-  if (fileNum <= 0) {
-    fprintf(stderr, "ERROR: directory:%s is empry\n", directoryName);
-    exit(0);
-  }
-
-  return fileNum;
-}
-
-static void shellParseDirectory(const char *directoryName, const char *prefix, char **fileArray, int totalFiles)
-{
-  char cmd[1024] = { 0 };
-  sprintf(cmd, "ls %s/*.%s | sort", directoryName, prefix);
-
-  char buf[1024] = { 0 };
-  if (taosSystem(cmd, buf, sizeof(buf)) < 0) {
-    fprintf(stderr, "ERROR: failed to execute:%s, error:%s\n", cmd, strerror(errno));
-    exit(0);
-  }
-
-  int fileNum = 0;
-  while (sscanf(buf, "%128s", fileArray[fileNum++])) {
-    if (strcmp(fileArray[fileNum-1], shellTablesSQLFile) == 0) {
-      fileNum--;
-    }
-    if (fileNum >= totalFiles) {
-      break;
-    }
-  }
-
-  if (fileNum != totalFiles) {
-    fprintf(stderr, "ERROR: directory:%s changed while read\n", directoryName);
-    exit(0);
-  }
-}
-
-static void shellCheckTablesSQLFile(const char *directoryName)
-{
-  sprintf(shellTablesSQLFile, "%s/tables.sql", directoryName);
-
-  if (taosFStatFile(shellTablesSQLFile, NULL, NULL) < 0) {
-    shellTablesSQLFile[0] = 0;
-  }
-}
-
-static void shellMallocSQLFiles()
-{
-  shellSQLFiles = (char**)taosMemoryCalloc(shellSQLFileNum, sizeof(char*));
-  for (int i = 0; i < shellSQLFileNum; i++) {
-    shellSQLFiles[i] = taosMemoryCalloc(1, TSDB_FILENAME_LEN);
-  }
-}
-
-static void shellGetDirectoryFileList(char *inputDir)
-{
-  if (!taosDirExist(inputDir)) {
-    fprintf(stderr, "ERROR: %s not exist\n", inputDir);
-    exit(0);
-  }
-
-  if (taosIsDir(inputDir)) {
-    shellCheckTablesSQLFile(inputDir);
-    shellSQLFileNum = shellGetFilesNum(inputDir, "sql");
-    int totalSQLFileNum = shellSQLFileNum;
-    if (shellTablesSQLFile[0] != 0) {
-      shellSQLFileNum--;
-    }
-    shellMallocSQLFiles();
-    shellParseDirectory(inputDir, "sql", shellSQLFiles, shellSQLFileNum);
-    fprintf(stdout, "\nstart to dispose %d files in %s\n", totalSQLFileNum, inputDir);
-  }
-  else {
-    fprintf(stderr, "ERROR: %s is not a directory\n", inputDir);
-    exit(0);
-  }
-}
-
-static void shellSourceFile(TAOS *con, char *fptr) {
-  wordexp_t full_path;
-  int       read_len = 0;
-  char *    cmd = taosMemoryMalloc(tsMaxSQLStringLen);
-  size_t    cmd_len = 0;
-  char *    line = NULL;
-
-  if (wordexp(fptr, &full_path, 0) != 0) {
-    fprintf(stderr, "ERROR: illegal file name\n");
-    taosMemoryFree(cmd);
-    return;
-  }
-
-  char *fname = full_path.we_wordv[0];
-  if (fname == NULL) {
-    fprintf(stderr, "ERROR: invalid filename\n");
-    taosMemoryFree(cmd);
-    return;
-  }
-
-  /*
-  if (access(fname, F_OK) != 0) {
-    fprintf(stderr, "ERROR: file %s is not exist\n", fptr);
-    
-    wordfree(&full_path);
-    taosMemoryFree(cmd);
-    return;
-  }
-  
-  if (access(fname, R_OK) != 0) {
-    fprintf(stderr, "ERROR: file %s is not readable\n", fptr);
-    
-    wordfree(&full_path);
-    taosMemoryFree(cmd);
-    return;
-  }
-  */
-
-  // FILE *f = fopen(fname, "r");
-  TdFilePtr pFile = taosOpenFile(fname, TD_FILE_READ | TD_FILE_STREAM);
-  if (pFile == NULL) {
-    fprintf(stderr, "ERROR: failed to open file %s\n", fname);
-    wordfree(&full_path);
-    taosMemoryFree(cmd);
-    return;
-  }
-
-  fprintf(stdout, "begin import file:%s\n", fname);
-
-  int lineNo = 0;
-  while ((read_len = taosGetLineFile(pFile, &line)) != -1) {
-    ++lineNo;
-    if (read_len >= tsMaxSQLStringLen) continue;
-    line[--read_len] = '\0';
-
-    if (read_len == 0 || isCommentLine(line)) {  // line starts with #
-      continue;
-    }
-
-    if (line[read_len - 1] == '\\') {
-      line[read_len - 1] = ' ';
-      memcpy(cmd + cmd_len, line, read_len);
-      cmd_len += read_len;
-      continue;
-    }
-
-    memcpy(cmd + cmd_len, line, read_len);
-    
-    TAOS_RES* pSql = taos_query(con, cmd);
-    int32_t code = taos_errno(pSql);
-    
-    if (code != 0) {
-      fprintf(stderr, "DB error: %s: %s (%d)\n", taos_errstr(pSql), fname, lineNo);
-    }
-    
-    /* free local resouce: allocated memory/metric-meta refcnt */
-    taos_free_result(pSql);
-
-    memset(cmd, 0, MAX_COMMAND_SIZE);
-    cmd_len = 0;
-  }
-
-  taosMemoryFree(cmd);
-  if(line != NULL) taosMemoryFree(line);
-  wordfree(&full_path);
-  taosCloseFile(&pFile);
-}
-
-void* shellImportThreadFp(void *arg)
-{
-  ShellThreadObj *pThread = (ShellThreadObj*)arg;
-  setThreadName("shellImportThrd");
-
-  for (int f = 0; f < shellSQLFileNum; ++f) {
-    if (f % pThread->totalThreads == pThread->threadIndex) {
-      char *SQLFileName = shellSQLFiles[f];
-      shellSourceFile(pThread->taos, SQLFileName);
-    }
-  }
-
-  return NULL;
-}
-
-static void shellRunImportThreads(SShellArguments* _args)
-{
-  TdThreadAttr thattr;
-  ShellThreadObj *threadObj = (ShellThreadObj *)taosMemoryCalloc(_args->threadNum, sizeof(ShellThreadObj));
-  for (int t = 0; t < _args->threadNum; ++t) {
-    ShellThreadObj *pThread = threadObj + t;
-    pThread->threadIndex = t;
-    pThread->totalThreads = _args->threadNum;
-    pThread->taos = taos_connect(_args->host, _args->user, _args->password, _args->database, tsDnodeShellPort);
-    if (pThread->taos == NULL) {
-      fprintf(stderr, "ERROR: thread:%d failed connect to TDengine, error:%s\n", pThread->threadIndex, "null taos"/*taos_errstr(pThread->taos)*/);
-      exit(0);
-    }
-
-    taosThreadAttrInit(&thattr);
-    taosThreadAttrSetDetachState(&thattr, PTHREAD_CREATE_JOINABLE);
-
-    if (taosThreadCreate(&(pThread->threadID), &thattr, shellImportThreadFp, (void*)pThread) != 0) {
-      fprintf(stderr, "ERROR: thread:%d failed to start\n", pThread->threadIndex);
-      exit(0);
-    }
-  }
-
-  for (int t = 0; t < _args->threadNum; ++t) {
-    taosThreadJoin(threadObj[t].threadID, NULL);
-  }
-
-  for (int t = 0; t < _args->threadNum; ++t) {
-    taos_close(threadObj[t].taos);
-  }
-  taosMemoryFree(threadObj);
-}
-
-void source_dir(TAOS* con, SShellArguments* _args) {
-  shellGetDirectoryFileList(_args->dir);
-  int64_t start = taosGetTimestampMs();
-
-  if (shellTablesSQLFile[0] != 0) {
-    shellSourceFile(con, shellTablesSQLFile);
-    int64_t end = taosGetTimestampMs();
-    fprintf(stdout, "import %s finished, time spent %.2f seconds\n", shellTablesSQLFile, (end - start) / 1000.0);
-  }
-
-  shellRunImportThreads(_args);
-  int64_t end = taosGetTimestampMs();
-  fprintf(stdout, "import %s finished, time spent %.2f seconds\n", _args->dir, (end - start) / 1000.0);
-}
diff --git a/tools/shell/src/backup/shellWindows.c b/tools/shell/src/backup/shellWindows.c
index 53bcb84cc8c75b507dc3b2f97c39f2887745af85..bf1c683d94ae7fac76870958925fd0ba4d3c0f85 100644
--- a/tools/shell/src/backup/shellWindows.c
+++ b/tools/shell/src/backup/shellWindows.c
@@ -70,7 +70,7 @@ void printHelp() {
 
 char g_password[SHELL_MAX_PASSWORD_LEN];
 
-void shellParseArgument(int argc, char *argv[], SShellArguments *arguments) {
+void shellParseArgs(int argc, char *argv[], SShellArgs *arguments) {
   for (int i = 1; i < argc; i++) {
     // for host
     if (strcmp(argv[i], "-h") == 0) {
@@ -231,7 +231,7 @@ void shellPrintContinuePrompt() { printf("%s", CONTINUE_PROMPT); }
 void shellPrintPrompt() { printf("%s", PROMPT_HEADER); }
 
 void updateBuffer(Command *cmd) {
-  if (regex_match(cmd->buffer, "(\\s+$)|(^$)", REG_EXTENDED)) strcat(cmd->command, " ");
+  if (shellRegexMatch(cmd->buffer, "(\\s+$)|(^$)", REG_EXTENDED)) strcat(cmd->command, " ");
   strcat(cmd->buffer, cmd->command);
 
   memset(cmd->command, 0, MAX_COMMAND_SIZE);
@@ -246,7 +246,7 @@ int isReadyGo(Command *cmd) {
   char *reg_str =
       "(^.*;\\s*$)|(^\\s*$)|(^\\s*exit\\s*$)|(^\\s*q\\s*$)|(^\\s*quit\\s*$)|(^"
       "\\s*clear\\s*$)";
-  if (regex_match(total, reg_str, REG_EXTENDED | REG_ICASE)) {
+  if (shellRegexMatch(total, reg_str, REG_EXTENDED | REG_ICASE)) {
     taosMemoryFree(total);
     return 1;
   }
@@ -299,7 +299,7 @@ int32_t shellReadCommand(TAOS *con, char command[]) {
   return 0;
 }
 
-void *shellLoopQuery(void *arg) {
+void *shellThreadLoop(void *arg) {
   TAOS *con = (TAOS *)arg;
   char *command = taosMemoryMalloc(MAX_COMMAND_SIZE);
   if (command == NULL) return NULL;
@@ -320,6 +320,6 @@ void *shellLoopQuery(void *arg) {
   return NULL;
 }
 
-void get_history_path(char *history) { sprintf(history, "C:/TDengine/%s", HISTORY_FILE); }
+void shellHistoryPath(char *history) { sprintf(history, "C:/TDengine/%s", HISTORY_FILE); }
 
-void exitShell() { exit(EXIT_SUCCESS); }
+void shellExit() { exit(EXIT_SUCCESS); }
diff --git a/tools/shell/src/backup/tnettest.h b/tools/shell/src/backup/tnettest.h
deleted file mode 100644
index 8a03b67628ffd460a4aa95ad4de8110b71472496..0000000000000000000000000000000000000000
--- a/tools/shell/src/backup/tnettest.h
+++ /dev/null
@@ -1,29 +0,0 @@
-/*
- * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
- *
- * This program is free software: you can use, redistribute, and/or modify
- * it under the terms of the GNU Affero General Public License, version 3
- * or later ("AGPL"), as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#ifndef TDENGINE_TNETTEST_H
-#define TDENGINE_TNETTEST_H
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-void taosNetTest(char *role, char *host, int32_t port, int32_t pkgLen, int32_t pkgNum, char *pkgType);
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif  // TDENGINE_TNETTEST_H
diff --git a/tools/shell/src/shellCommand.c b/tools/shell/src/shellCommand.c
index c9cd57fc17c95722cdcb104e5257068c53ba589b..1ec222fcc89fd95eb935c39c54e51d83440ce48e 100644
--- a/tools/shell/src/shellCommand.c
+++ b/tools/shell/src/shellCommand.c
@@ -214,7 +214,7 @@ void positionCursor(int step, int direction) {
 void updateBuffer(Command *cmd) {
   assert(cmd->cursorOffset <= cmd->commandSize && cmd->endOffset >= cmd->screenOffset);
 
-  if (regex_match(cmd->buffer, "(\\s+$)|(^$)", REG_EXTENDED)) strcat(cmd->command, " ");
+  if (shellRegexMatch(cmd->buffer, "(\\s+$)|(^$)", REG_EXTENDED)) strcat(cmd->command, " ");
   strcat(cmd->buffer, cmd->command);
   cmd->bufferSize += cmd->commandSize;
 
@@ -236,7 +236,7 @@ int isReadyGo(Command *cmd) {
   char *reg_str =
       "(^.*;\\s*$)|(^\\s*$)|(^\\s*exit\\s*$)|(^\\s*q\\s*$)|(^\\s*quit\\s*$)|(^"
       "\\s*clear\\s*$)";
-  if (regex_match(total, reg_str, REG_EXTENDED | REG_ICASE)) {
+  if (shellRegexMatch(total, reg_str, REG_EXTENDED | REG_ICASE)) {
     taosMemoryFree(total);
     return 1;
   }
diff --git a/tools/shell/src/shellEngine.c b/tools/shell/src/shellEngine.c
index e1a1924b2dd9f51f8f73746d6d1896410f2f643c..9a4ef8b65a9fee2dc2929db7904ff727f7e7c982 100644
--- a/tools/shell/src/shellEngine.c
+++ b/tools/shell/src/shellEngine.c
@@ -68,7 +68,7 @@ extern TAOS   *taos_connect_auth(const char *ip, const char *user, const char *a
 /*
  * FUNCTION: Initialize the shell.
  */
-TAOS *shellInit(SShellArguments *_args) {
+TAOS *shellInit(SShellArgs *_args) {
   printf("\n");
   if (!_args->is_use_passwd) {
 #ifdef TD_WINDOWS
@@ -108,7 +108,7 @@ TAOS *shellInit(SShellArguments *_args) {
   }
 
   /* Read history TODO : release resources here*/
-  read_history();
+  shellReadHistory();
 
   // Check if it is temperory run
   if (_args->commands != NULL || _args->file[0] != 0) {
@@ -118,29 +118,14 @@ TAOS *shellInit(SShellArguments *_args) {
     }
 
     if (_args->file[0] != 0) {
-      source_file(con, _args->file);
+      shellSourceFile(con, _args->file);
     }
 
     taos_close(con);
-    write_history();
+    shellWriteHistory();
     exit(EXIT_SUCCESS);
   }
 
-#if 0
-#ifndef WINDOWS
-  if (_args->dir[0] != 0) {
-    source_dir(con, _args);
-    taos_close(con);
-    exit(EXIT_SUCCESS);
-  }
-
-  if (_args->check != 0) {
-    shellCheck(con, _args);
-    taos_close(con);
-    exit(EXIT_SUCCESS);
-  }
-#endif
-#endif
 
   return con;
 }
@@ -161,22 +146,22 @@ static int32_t shellRunSingleCommand(TAOS *con, char *command) {
   }
 
   // Analyse the command.
-  if (regex_match(command, "^[ \t]*(quit|q|exit)[ \t;]*$", REG_EXTENDED | REG_ICASE)) {
+  if (shellRegexMatch(command, "^[ \t]*(quit|q|exit)[ \t;]*$", REG_EXTENDED | REG_ICASE)) {
     taos_close(con);
-    write_history();
+    shellWriteHistory();
 #ifdef WINDOWS
     exit(EXIT_SUCCESS);
 #endif
     return -1;
   }
 
-  if (regex_match(command, "^[\t ]*clear[ \t;]*$", REG_EXTENDED | REG_ICASE)) {
+  if (shellRegexMatch(command, "^[\t ]*clear[ \t;]*$", REG_EXTENDED | REG_ICASE)) {
     // If clear the screen.
     system("clear");
     return 0;
   }
 
-  if (regex_match(command, "^[\t ]*set[ \t]+max_binary_display_width[ \t]+(default|[1-9][0-9]*)[ \t;]*$",
+  if (shellRegexMatch(command, "^[\t ]*set[ \t]+max_binary_display_width[ \t]+(default|[1-9][0-9]*)[ \t;]*$",
                   REG_EXTENDED | REG_ICASE)) {
     strtok(command, " \t");
     strtok(NULL, " \t");
@@ -189,17 +174,17 @@ static int32_t shellRunSingleCommand(TAOS *con, char *command) {
     return 0;
   }
 
-  if (regex_match(command, "^[ \t]*source[\t ]+[^ ]+[ \t;]*$", REG_EXTENDED | REG_ICASE)) {
+  if (shellRegexMatch(command, "^[ \t]*source[\t ]+[^ ]+[ \t;]*$", REG_EXTENDED | REG_ICASE)) {
     /* If source file. */
     char *c_ptr = strtok(command, " ;");
     assert(c_ptr != NULL);
     c_ptr = strtok(NULL, " ;");
     assert(c_ptr != NULL);
-    source_file(con, c_ptr);
+    shellSourceFile(con, c_ptr);
     return 0;
   }
 
-  shellRunCommandOnServer(con, command);
+  shellRunCommandImp(con, command);
   return 0;
 }
 
@@ -294,7 +279,7 @@ void freeResultWithRid(int64_t rid) {
 #endif
 }
 
-void shellRunCommandOnServer(TAOS *con, char command[]) {
+void shellRunCommandImp(TAOS *con, char command[]) {
   int64_t   st, et;
   wordexp_t full_path;
   char     *sptr = NULL;
@@ -330,13 +315,13 @@ void shellRunCommandOnServer(TAOS *con, char command[]) {
 
   TAOS_RES *pSql = taos_query(con, command);
   if (taos_errno(pSql)) {
-    taos_error(pSql, st);
+    shellPrintError(pSql, st);
     return;
   }
 
   int64_t oresult = atomic_load_64(&result);
 
-  if (regex_match(command, "^\\s*use\\s+[a-zA-Z0-9_]+\\s*;\\s*$", REG_EXTENDED | REG_ICASE)) {
+  if (shellRegexMatch(command, "^\\s*use\\s+[a-zA-Z0-9_]+\\s*;\\s*$", REG_EXTENDED | REG_ICASE)) {
     fprintf(stdout, "Database changed.\n\n");
     fflush(stdout);
 
@@ -383,14 +368,14 @@ void shellRunCommandOnServer(TAOS *con, char command[]) {
 }
 
 /* Function to do regular expression check */
-int regex_match(const char *s, const char *reg, int cflags) {
+int shellRegexMatch(const char *s, const char *reg, int cflags) {
   regex_t regex;
   char    msgbuf[100] = {0};
 
   /* Compile regular expression */
   if (regcomp(&regex, reg, cflags) != 0) {
     fprintf(stderr, "Fail to compile regex");
-    exitShell();
+    shellExit();
   }
 
   /* Execute regular expression */
@@ -405,7 +390,7 @@ int regex_match(const char *s, const char *reg, int cflags) {
     regerror(reti, &regex, msgbuf, sizeof(msgbuf));
     fprintf(stderr, "Regex match failed: %s\n", msgbuf);
     regfree(&regex);
-    exitShell();
+    shellExit();
   }
 
   return 0;
@@ -695,7 +680,7 @@ bool isSelectQuery(TAOS_RES *tres) {
 #if 0
   char *sql = tscGetSqlStr(tres);
 
-  if (regex_match(sql, "^[\t ]*select[ \t]*", REG_EXTENDED | REG_ICASE)) {
+  if (shellRegexMatch(sql, "^[\t ]*select[ \t]*", REG_EXTENDED | REG_ICASE)) {
     return true;
   }
 #endif
@@ -900,7 +885,7 @@ int shellDumpResult(TAOS_RES *tres, char *fname, int *error_no, bool vertical) {
   return numOfRows;
 }
 
-void read_history() {
+void shellReadHistory() {
   // Initialize history
   memset(history.hist, 0, sizeof(char *) * MAX_HISTORY_SIZE);
   history.hstart = 0;
@@ -909,7 +894,7 @@ void read_history() {
   int   read_size = 0;
 
   char f_history[TSDB_FILENAME_LEN];
-  get_history_path(f_history);
+  shellHistoryPath(f_history);
 
   // FILE *f = fopen(f_history, "r");
   TdFilePtr pFile = taosOpenFile(f_history, TD_FILE_READ | TD_FILE_STREAM);
@@ -937,9 +922,9 @@ void read_history() {
   taosCloseFile(&pFile);
 }
 
-void write_history() {
+void shellWriteHistory() {
   char f_history[TSDB_FILENAME_LEN];
-  get_history_path(f_history);
+  shellHistoryPath(f_history);
 
   // FILE *f = fopen(f_history, "w");
   TdFilePtr pFile = taosOpenFile(f_history, TD_FILE_CREATE | TD_FILE_WRITE | TD_FILE_TRUNC | TD_FILE_STREAM);
@@ -960,7 +945,7 @@ void write_history() {
   taosCloseFile(&pFile);
 }
 
-void taos_error(TAOS_RES *tres, int64_t st) {
+void shellPrintError(TAOS_RES *tres, int64_t st) {
   int64_t et = taosGetTimestampUs();
   atomic_store_ptr(&result, 0);
   fprintf(stderr, "\nDB error: %s (%.6fs)\n", taos_errstr(tres), (et - st) / 1E6);
@@ -970,10 +955,10 @@ void taos_error(TAOS_RES *tres, int64_t st) {
 int isCommentLine(char *line) {
   if (line == NULL) return 1;
 
-  return regex_match(line, "^\\s*#.*", REG_EXTENDED);
+  return shellRegexMatch(line, "^\\s*#.*", REG_EXTENDED);
 }
 
-void source_file(TAOS *con, char *fptr) {
+void shellSourceFile(TAOS *con, char *fptr) {
   wordexp_t full_path;
   int       read_len = 0;
   char     *cmd = taosMemoryCalloc(1, TSDB_MAX_ALLOWED_SQL_LEN + 1);
diff --git a/tools/shell/src/shellMain.c b/tools/shell/src/shellMain.c
index 83b0f48677734f4329c827487e5ec61bdc718e40..7c7d80cb30fb531fc4505d37dce0275ef383684c 100644
--- a/tools/shell/src/shellMain.c
+++ b/tools/shell/src/shellMain.c
@@ -64,7 +64,7 @@ static struct argp_option options[] = {
 static error_t parse_opt(int key, char *arg, struct argp_state *state) {
   /* Get the input argument from argp_parse, which we
   know is a pointer to our arguments structure. */
-  SShellArguments *arguments = state->input;
+  SShellArgs *arguments = state->input;
   wordexp_t        full_path;
 
   switch (key) {
@@ -188,7 +188,7 @@ char LINUXCLIENT_VERSION[] =
     "Copyright (c) 2020 by TAOS Data, Inc. All rights reserved.\n\n";
 char g_password[SHELL_MAX_PASSWORD_LEN];
 
-static void parse_args(int argc, char *argv[], SShellArguments *arguments) {
+static void parse_args(int argc, char *argv[], SShellArgs *arguments) {
   for (int i = 1; i < argc; i++) {
     if ((strncmp(argv[i], "-p", 2) == 0) || (strncmp(argv[i], "--password", 10) == 0)) {
       printf(LINUXCLIENT_VERSION, tsOsName, taos_get_client_info());
@@ -212,7 +212,7 @@ static void parse_args(int argc, char *argv[], SShellArguments *arguments) {
   }
 }
 
-void shellParseArgument(int argc, char *argv[], SShellArguments *arguments) {
+int32_t shellParseArgs(int argc, char *argv[], SShellArgs *arguments) {
   static char verType[32] = {0};
   sprintf(verType, "version: %s\n", version);
 
@@ -232,6 +232,8 @@ void shellParseArgument(int argc, char *argv[], SShellArguments *arguments) {
     abort();
 #endif
   }
+
+  return 0;
 }
 
 int32_t shellReadCommand(TAOS *con, char *command) {
@@ -275,8 +277,8 @@ int32_t shellReadCommand(TAOS *con, char *command) {
           printf("\n");
           taos_close(con);
           // write the history
-          write_history();
-          exitShell();
+          shellWriteHistory();
+          shellExit();
           break;
         case 5:  // ctrl E
           positionCursorEnd(&cmd);
@@ -392,7 +394,7 @@ int32_t shellReadCommand(TAOS *con, char *command) {
   return 0;
 }
 
-void *shellLoopQuery(void *arg) {
+void *shellThreadLoop(void *arg) {
   if (indicator) {
     getOldTerminalMode();
     indicator = 0;
@@ -400,9 +402,9 @@ void *shellLoopQuery(void *arg) {
 
   TAOS *con = (TAOS *)arg;
 
-  setThreadName("shellLoopQuery");
+  setThreadName("shellThreadLoop");
 
-  taosThreadCleanupPush(cleanup_handler, NULL);
+  taosThreadCleanupPush(shellCleanup, NULL);
 
   char *command = taosMemoryMalloc(MAX_COMMAND_SIZE);
   if (command == NULL) {
@@ -424,14 +426,14 @@ void *shellLoopQuery(void *arg) {
   } while (shellRunCommand(con, command) == 0);
 
   taosMemoryFreeClear(command);
-  exitShell();
+  shellExit();
 
   taosThreadCleanupPop(1);
 
   return NULL;
 }
 
-void get_history_path(char *_history) { snprintf(_history, TSDB_FILENAME_LEN, "%s/%s", getenv("HOME"), HISTORY_FILE); }
+void shellHistoryPath(char *_history) { snprintf(_history, TSDB_FILENAME_LEN, "%s/%s", getenv("HOME"), HISTORY_FILE); }
 
 void clearScreen(int ecmd_pos, int cursor_pos) {
   struct winsize w;
@@ -527,9 +529,9 @@ void showOnScreen(Command *cmd) {
   fflush(stdout);
 }
 
-void cleanup_handler(void *arg) { resetTerminalMode(); }
+void shellCleanup(void *arg) { resetTerminalMode(); }
 
-void exitShell() {
+void shellExit() {
   taos_cleanup();
   exit(EXIT_SUCCESS);
 }
@@ -547,7 +549,7 @@ void *cancelHandler(void *arg) {
 
     resetTerminalMode();
     printf("\nReceive ctrl+c or other signal, quit shell.\n");
-    exitShell();
+    shellExit();
   }
 
   return NULL;
@@ -574,7 +576,7 @@ int checkVersion() {
 }
 
 // Global configurations
-SShellArguments args = {
+SShellArgs args = {
     .host = NULL,
     .user = NULL,
     .database = NULL,
@@ -604,13 +606,13 @@ void shellDumpConfig() {
     exit(EXIT_FAILURE);
   }
   cfgDumpCfg(pCfg, 0, 1);
-  exitShell();
+  shellExit();
 }
 
 void shellTestNetWork() {
   if (args.netTestRole && args.netTestRole[0] != 0) {
     taosNetTest(args.netTestRole, args.host, args.port, args.pktLen, args.pktNum, args.pktType);
-    exitShell();
+    shellExit();
   }
 }
 
@@ -648,18 +650,18 @@ void shellCheckServerStatus() {
     }
   } while (1);
 
-  exitShell();
+  shellExit();
 }
 
 void shellExecute() {
   TAOS *con = shellInit(&args);
   if (con == NULL) {
-    exitShell();
+    shellExit();
   }
 
   if (tsem_init(&cancelSem, 0, 0) != 0) {
     printf("failed to create cancel semphore\n");
-    exitShell();
+    shellExit();
   }
 
   TdThread spid;
@@ -673,15 +675,15 @@ void shellExecute() {
   shellGetGrantInfo(con);
 
   while (1) {
-    taosThreadCreate(&pid, NULL, shellLoopQuery, con);
+    taosThreadCreate(&pid, NULL, shellThreadLoop, con);
     taosThreadJoin(pid, NULL);
   }
 }
 
 int main(int argc, char *argv[]) {
-  if (!checkVersion()) exitShell();
+  if (!checkVersion()) shellExit();
 
-  shellParseArgument(argc, argv, &args);
+  shellParseArgs(argc, argv, &args);
 
   taos_init();
   shellDumpConfig();