diff --git a/src/kit/shell/src/shellEngine.c b/src/kit/shell/src/shellEngine.c
index e28c691a8986fce0bcb7a04b8bb1e5f7f5c6605c..044e167af7938d3ce1d15e9e097c52cc9a1ef2e1 100644
--- a/src/kit/shell/src/shellEngine.c
+++ b/src/kit/shell/src/shellEngine.c
@@ -474,7 +474,7 @@ static int dumpResultToFile(const char* fname, TAOS_RES* tres) {
   } while( row != NULL);
 
   result = NULL;
-  taos_free_result(tres);
+  //taos_free_result(tres);
   fclose(fp);
 
   return numOfRows;
@@ -803,6 +803,7 @@ void source_file(TAOS *con, char *fptr) {
 
   char *fname = full_path.we_wordv[0];
 
+  /*
   if (access(fname, F_OK) != 0) {
     fprintf(stderr, "ERROR: file %s is not exist\n", fptr);
     
@@ -810,6 +811,7 @@ void source_file(TAOS *con, char *fptr) {
     free(cmd);
     return;
   }
+  */
   
   FILE *f = fopen(fname, "r");
   if (f == NULL) {
@@ -849,7 +851,7 @@ void source_file(TAOS *con, char *fptr) {
 
 void shellGetGrantInfo(void *con) {
   return;
-
+#if 0
   char sql[] = "show grants";
 
   TAOS_RES* tres = taos_query(con, sql);
@@ -900,4 +902,5 @@ void shellGetGrantInfo(void *con) {
   }
 
   fprintf(stdout, "\n");
+  #endif
 }
diff --git a/src/kit/shell/src/shellImport.c b/src/kit/shell/src/shellImport.c
index 347f99671db1bc9147c98d97ec708a3bf8bcf689..ba123ac2d4b51ec8a5d30460dae302c585bf051a 100644
--- a/src/kit/shell/src/shellImport.c
+++ b/src/kit/shell/src/shellImport.c
@@ -73,7 +73,7 @@ static void shellParseDirectory(const char *directoryName, const char *prefix, c
   }
 
   int fileNum = 0;
-  while (fscanf(fp, "%s", fileArray[fileNum++])) {
+  while (fscanf(fp, "%128s", fileArray[fileNum++])) {
     if (strcmp(fileArray[fileNum-1], shellTablesSQLFile) == 0) {
       fileNum--;
     }
@@ -150,9 +150,11 @@ static void shellSourceFile(TAOS *con, char *fptr) {
   char *fname = full_path.we_wordv[0];
   if (fname == NULL) {
     fprintf(stderr, "ERROR: invalid filename\n");
+    free(cmd);
     return;
   }
 
+  /*
   if (access(fname, F_OK) != 0) {
     fprintf(stderr, "ERROR: file %s is not exist\n", fptr);
     
@@ -168,6 +170,7 @@ static void shellSourceFile(TAOS *con, char *fptr) {
     free(cmd);
     return;
   }
+  */
 
   FILE *f = fopen(fname, "r");
   if (f == NULL) {
diff --git a/src/kit/shell/src/shellLinux.c b/src/kit/shell/src/shellLinux.c
index 829ceb9e5f19107ef65c5a3884bffd8a03e593b8..0325fa34f92914ab1b109eba874d66fdf1fb1173 100644
--- a/src/kit/shell/src/shellLinux.c
+++ b/src/kit/shell/src/shellLinux.c
@@ -162,7 +162,7 @@ void shellReadCommand(TAOS *con, char *command) {
   // Read input.
   char c;
   while (1) {
-    c = getchar();
+    c = (char)getchar(); // getchar() return an 'int' value
 
     if (c < 0) {  // For UTF-8
       int count = countPrefixOnes(c);
diff --git a/src/kit/taosdemo/taosdemo.c b/src/kit/taosdemo/taosdemo.c
index 4a455271fff51e1bd9438ce01d044eee3760f6c2..1dd31779fe9c786c0bcc86487edbe87dc24faa15 100644
--- a/src/kit/taosdemo/taosdemo.c
+++ b/src/kit/taosdemo/taosdemo.c
@@ -34,6 +34,7 @@
 #include <wordexp.h>
 
 #include "taos.h"
+#include "tutil.h"
 
 extern char configDir[];
 
@@ -82,7 +83,7 @@ typedef struct DemoArguments {
   bool   insert_only;
   char  *output_file;
   int    mode;
-  char  *datatype[MAX_NUM_DATATYPE];
+  char  *datatype[MAX_NUM_DATATYPE+1];
   int    len_of_binary;
   int    num_of_CPR;
   int    num_of_threads;
@@ -432,7 +433,7 @@ int main(int argc, char *argv[]) {
           tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
   printf("###################################################################\n\n");
   printf("Press enter key to continue");
-  getchar();
+  (void)getchar();
 
   fprintf(fp, "###################################################################\n");
   fprintf(fp, "# Server IP:                         %s:%hu\n", ip_addr == NULL ? "localhost" : ip_addr, port);
@@ -845,10 +846,10 @@ void *syncWrite(void *sarg) {
       pstr += sprintf(pstr, "insert into %s.%s%d values", winfo->db_name, winfo->tb_prefix, tID);
       int k;
       for (k = 0; k < winfo->nrecords_per_request;) {
-        int rand_num = rand() % 100;
+        int rand_num = trand() % 100;
         int len = -1;
         if (winfo->data_of_order ==1 && rand_num < winfo->data_of_rate) {
-          long d = tmp_time - rand() % 1000000 + rand_num;
+          long d = tmp_time - trand() % 1000000 + rand_num;
           len = generateData(data, data_type, ncols_per_record, d, len_of_binary);
         } else {
           len = generateData(data, data_type, ncols_per_record, tmp_time += 1000, len_of_binary);
@@ -940,10 +941,10 @@ void callBack(void *param, TAOS_RES *res, int code) {
   pstr += sprintf(pstr, "insert into %s values", tb_info->tb_name);
 
   for (int i = 0; i < tb_info->nrecords_per_request; i++) {
-    int rand_num = rand() % 100;
+    int rand_num = trand() % 100;
     if (tb_info->data_of_order ==1 && rand_num < tb_info->data_of_rate)
     {
-      long d = tmp_time - rand() % 1000000 + rand_num;
+      long d = tmp_time - trand() % 1000000 + rand_num;
       generateData(data, datatype, ncols_per_record, d, len_of_binary);
     } else 
     {
@@ -985,22 +986,27 @@ int32_t generateData(char *res, char **data_type, int num_of_cols, int64_t times
     }
   }
 
+  if (0 == c) {
+    perror("data type error!");
+    exit(-1);
+  }
+
   for (int i = 0; i < num_of_cols; i++) {
     if (strcasecmp(data_type[i % c], "tinyint") == 0) {
-      pstr += sprintf(pstr, ", %d", (int)(rand() % 128));
+      pstr += sprintf(pstr, ", %d", (int)(trand() % 128));
     } else if (strcasecmp(data_type[i % c], "smallint") == 0) {
-      pstr += sprintf(pstr, ", %d", (int)(rand() % 32767));
+      pstr += sprintf(pstr, ", %d", (int)(trand() % 32767));
     } else if (strcasecmp(data_type[i % c], "int") == 0) {
-      pstr += sprintf(pstr, ", %d", (int)(rand() % 10)); 
+      pstr += sprintf(pstr, ", %d", (int)(trand() % 10)); 
     } else if (strcasecmp(data_type[i % c], "bigint") == 0) {
-      pstr += sprintf(pstr, ", %" PRId64, rand() % 2147483648);
+      pstr += sprintf(pstr, ", %" PRId64, trand() % 2147483648);
     } else if (strcasecmp(data_type[i % c], "float") == 0) {
-      pstr += sprintf(pstr, ", %10.4f", (float)(rand() / 1000));
+      pstr += sprintf(pstr, ", %10.4f", (float)(trand() / 1000));
     } else if (strcasecmp(data_type[i % c], "double") == 0) {
-      double t = (double)(rand() / 1000000);
+      double t = (double)(trand() / 1000000);
       pstr += sprintf(pstr, ", %20.8f", t);
     } else if (strcasecmp(data_type[i % c], "bool") == 0) {
-      bool b = rand() & 1;
+      bool b = trand() & 1;
       pstr += sprintf(pstr, ", %s", b ? "true" : "false");
     } else if (strcasecmp(data_type[i % c], "binary") == 0) {
       char s[len_of_binary];
@@ -1026,7 +1032,7 @@ void rand_string(char *str, int size) {
     --size;
     int n;
     for (n = 0; n < size; n++) {
-      int key = rand() % (int)(sizeof charset - 1);
+      int key = trand() % (int)(sizeof charset - 1);
       str[n] = charset[key];
     }
     str[n] = 0;
diff --git a/src/kit/taosdump/taosdump.c b/src/kit/taosdump/taosdump.c
index ccef783709e6cee69ff1178d939716b33a410e39..46b14d6e56b5a526a9d84d40735ffe3f6292abcd 100644
--- a/src/kit/taosdump/taosdump.c
+++ b/src/kit/taosdump/taosdump.c
@@ -229,7 +229,7 @@ static error_t parse_opt(int key, char *arg, struct argp_state *state) {
         fprintf(stderr, "Invalid path %s\n", arg);
         return -1;
       }
-      strcpy(arguments->output, full_path.we_wordv[0]);
+      tstrncpy(arguments->output, full_path.we_wordv[0], TSDB_FILENAME_LEN);
       wordfree(&full_path);
       break;
     case 'i':
@@ -411,7 +411,7 @@ int taosGetTableRecordInfo(char *table, STableRecordInfo *pTableRecordInfo) {
   if ((row = taos_fetch_row(result)) != NULL) {
     isSet = true;
     pTableRecordInfo->isMetric = true;
-    strcpy(pTableRecordInfo->tableRecord.metric, table);
+    tstrncpy(pTableRecordInfo->tableRecord.metric, table, TSDB_TABLE_NAME_LEN);
   }
 
   taos_free_result(result);
@@ -642,9 +642,12 @@ int taosDumpDb(SDbInfo *dbInfo, SDumpArguments *arguments, FILE *fp) {
 
   taos_free_result(result);
 
-  lseek(fd, 0, SEEK_SET);
+  (void)lseek(fd, 0, SEEK_SET);
 
-  while (read(fd, &tableRecord, sizeof(STableRecord)) > 0) {
+  while (1) {
+    ssize_t ret = read(fd, &tableRecord, sizeof(STableRecord));
+    if (ret <= 0) break;
+    
     tableRecord.name[sizeof(tableRecord.name) - 1] = 0;
     tableRecord.metric[sizeof(tableRecord.metric) - 1] = 0;
     taosDumpTable(tableRecord.name, tableRecord.metric, arguments, fp);
@@ -807,7 +810,7 @@ int taosGetTableDes(char *table, STableDef *tableDes) {
 
   TAOS_FIELD *fields = taos_fetch_fields(result);
 
-  strcpy(tableDes->name, table);
+  tstrncpy(tableDes->name, table, TSDB_COL_NAME_LEN);
 
   while ((row = taos_fetch_row(result)) != NULL) {
     strncpy(tableDes->cols[count].field, (char *)row[TSDB_DESCRIBE_METRIC_FIELD_INDEX],
@@ -903,16 +906,19 @@ int32_t taosDumpMetric(char *metric, SDumpArguments *arguments, FILE *fp) {
   taos_free_result(result);
   result = NULL;
 
-  lseek(fd, 0, SEEK_SET);
+  (void)lseek(fd, 0, SEEK_SET);
 
-  while (read(fd, &tableRecord, sizeof(STableRecord)) > 0) {
+  while (1) {
+    ssize_t ret = read(fd, &tableRecord, sizeof(STableRecord));
+    if (ret <= 0) break;
+    
     tableRecord.name[sizeof(tableRecord.name) - 1] = 0;
     tableRecord.metric[sizeof(tableRecord.metric) - 1] = 0;
     taosDumpTable(tableRecord.name, tableRecord.metric, arguments, fp);
   }
 
   tclose(fd);
-  remove(".table.tmp");
+  (void)remove(".table.tmp");
 
   return 0;
 }
@@ -1004,7 +1010,7 @@ int taosDumpTableData(FILE *fp, char *tbname, SDumpArguments *arguments) {
           break;
       }
     }
-    pstr += sprintf(pstr, ")");
+    sprintf(pstr, ")");
 
     count++;
     fprintf(fp, "%s", buffer);
@@ -1327,7 +1333,7 @@ int convertNCharToReadable(char *str, int size, char *buf, int bufsize) {
 
     if ((int)wc < 256) {
       pbuf = stpcpy(pbuf, ascii_literal_list[(int)wc]);
-    } else {
+    } else if (byte_width > 0) {
       memcpy(pbuf, pstr, byte_width);
       pbuf += byte_width;
     }
diff --git a/src/os/linux/src/linuxSysPara.c b/src/os/linux/src/linuxSysPara.c
index 0e76ab00469540f7c31a2508ec51ff828d9e8d4c..31ae33cdfc7c7c71064f3ee21bc690ae57656596 100644
--- a/src/os/linux/src/linuxSysPara.c
+++ b/src/os/linux/src/linuxSysPara.c
@@ -162,7 +162,7 @@ static void taosGetSystemTimezone() {
   FILE *f = fopen("/etc/timezone", "r");
   char  buf[65] = {0};
   if (f != NULL) {
-    fread(buf, 64, 1, f);
+    (void)fread(buf, 64, 1, f);
     fclose(f);
   }
 
@@ -547,7 +547,7 @@ void taosSetCoreDump() {
   struct rlimit rlim;
   struct rlimit rlim_new;
   if (getrlimit(RLIMIT_CORE, &rlim) == 0) {
-    uPrint("the old unlimited para: rlim_cur=%d, rlim_max=%d", rlim.rlim_cur, rlim.rlim_max);
+    uPrint("the old unlimited para: rlim_cur=%d, rlim_max=%" PRIu64, rlim.rlim_cur, rlim.rlim_max);
     rlim_new.rlim_cur = RLIM_INFINITY;
     rlim_new.rlim_max = RLIM_INFINITY;
     if (setrlimit(RLIMIT_CORE, &rlim_new) != 0) {
@@ -559,7 +559,7 @@ void taosSetCoreDump() {
   }
 
   if (getrlimit(RLIMIT_CORE, &rlim) == 0) {
-    uPrint("the new unlimited para: rlim_cur=%d, rlim_max=%d", rlim.rlim_cur, rlim.rlim_max);
+    uPrint("the new unlimited para: rlim_cur=%d, rlim_max=%" PRIu64, rlim.rlim_cur, rlim.rlim_max);
   }
 
 #ifndef _TD_ARM_
@@ -586,7 +586,7 @@ void taosSetCoreDump() {
       uPrint("_sysctl(kern_core_uses_pid) set fail: %s", strerror(errno));
   }
   
-  uPrint("The old core_uses_pid[%d]: %d", old_len, old_usespid);
+  uPrint("The old core_uses_pid[%" PRIu64 "]: %d", old_len, old_usespid);
 
 
   old_usespid = 0;
@@ -603,7 +603,7 @@ void taosSetCoreDump() {
       uPrint("_sysctl(kern_core_uses_pid) get fail: %s", strerror(errno));
   }
   
-  uPrint("The new core_uses_pid[%d]: %d", old_len, old_usespid);
+  uPrint("The new core_uses_pid[%" PRIu64 "]: %d", old_len, old_usespid);
 #endif
   
 #if 0
diff --git a/src/util/inc/tutil.h b/src/util/inc/tutil.h
index a314f0e31ddde3e1e58c9c8ba7bcfd89efe4b1d2..94084b5638a497e07a6ab4bd29fa51749d671dfb 100644
--- a/src/util/inc/tutil.h
+++ b/src/util/inc/tutil.h
@@ -119,6 +119,8 @@ extern "C" {
 
 uint32_t taosRand(void);
 
+uint32_t trand(void);
+
 size_t twcslen(const wchar_t *wcs);
 
 int32_t strdequote(char *src);
diff --git a/src/util/src/tnote.c b/src/util/src/tnote.c
index a8d9e8d416ce9c9ee2653a665ecb080930e2c7ab..20c77d4fbe14b9f8151abe314e9e1df369931edc 100644
--- a/src/util/src/tnote.c
+++ b/src/util/src/tnote.c
@@ -128,10 +128,12 @@ int taosOpenNewNote(taosNoteInfo * pNote)
 
 bool taosCheckNoteIsOpen(char *noteName, taosNoteInfo * pNote)
 {
+    /*
     int exist = access(noteName, F_OK);
     if (exist != 0) {
         return false;
     }
+    */
 
     int fd = open(noteName, O_WRONLY | O_CREAT, S_IRWXU | S_IRWXG | S_IRWXO);
     if (fd < 0) {
diff --git a/src/util/src/tutil.c b/src/util/src/tutil.c
index aa5bfe322a9e0912ae13eecdaa75783505986648..ccdf7111a7264726d35a4bf938e851b1fa5c3edf 100644
--- a/src/util/src/tutil.c
+++ b/src/util/src/tutil.c
@@ -55,6 +55,25 @@ uint32_t taosRand(void)
 */
   return rand();
 }
+
+uint32_t trand(void)
+{
+  int fd;
+  int seed;
+  
+  fd = open("/dev/urandom", 0);
+  if (fd < 0) {
+    seed = time(0);
+  } else {
+    int len = read(fd, &seed, sizeof(seed));
+    if (len < 0) {
+      seed = time(0);
+    }  
+    close(fd);
+  }
+
+  return (uint32_t)seed;
+}
 #endif
 
 size_t twcslen(const wchar_t *wcs) {