diff --git a/src/kit/shell/src/shellLinux.c b/src/kit/shell/src/shellLinux.c
index 0325fa34f92914ab1b109eba874d66fdf1fb1173..9d4de06b0fb2297412fea0fdb24c326071ee8222 100644
--- a/src/kit/shell/src/shellLinux.c
+++ b/src/kit/shell/src/shellLinux.c
@@ -168,7 +168,7 @@ void shellReadCommand(TAOS *con, char *command) {
       int count = countPrefixOnes(c);
       utf8_array[0] = c;
       for (int k = 1; k < count; k++) {
-        c = getchar();
+        c = (char)getchar();
         utf8_array[k] = c;
       }
       insertChar(&cmd, utf8_array, count);
@@ -214,10 +214,10 @@ void shellReadCommand(TAOS *con, char *command) {
           break;
       }
     } else if (c == '\033') {
-      c = getchar();
+      c = (char)getchar();
       switch (c) {
         case '[':
-          c = getchar();
+          c = (char)getchar();
           switch (c) {
             case 'A':  // Up arrow
               if (hist_counter != history.hstart) {
@@ -244,35 +244,35 @@ void shellReadCommand(TAOS *con, char *command) {
               moveCursorLeft(&cmd);
               break;
             case '1':
-              if ((c = getchar()) == '~') {
+              if ((c = (char)getchar()) == '~') {
                 // Home key
                 positionCursorHome(&cmd);
               }
               break;
             case '2':
-              if ((c = getchar()) == '~') {
+              if ((c = (char)getchar()) == '~') {
                 // Insert key
               }
               break;
             case '3':
-              if ((c = getchar()) == '~') {
+              if ((c = (char)getchar()) == '~') {
                 // Delete key
                 deleteChar(&cmd);
               }
               break;
             case '4':
-              if ((c = getchar()) == '~') {
+              if ((c = (char)getchar()) == '~') {
                 // End key
                 positionCursorEnd(&cmd);
               }
               break;
             case '5':
-              if ((c = getchar()) == '~') {
+              if ((c = (char)getchar()) == '~') {
                 // Page up key
               }
               break;
             case '6':
-              if ((c = getchar()) == '~') {
+              if ((c = (char)getchar()) == '~') {
                 // Page down key
               }
               break;
diff --git a/src/kit/taosdemo/taosdemo.c b/src/kit/taosdemo/taosdemo.c
index 1dd31779fe9c786c0bcc86487edbe87dc24faa15..e4b84fc8e8cf7412b47078a41b8e27939811fc2f 100644
--- a/src/kit/taosdemo/taosdemo.c
+++ b/src/kit/taosdemo/taosdemo.c
@@ -551,8 +551,8 @@ int main(int argc, char *argv[]) {
   for (int i = 0; i < threads; i++) {
     info *t_info = infos + i;
     t_info->threadID = i;
-    strcpy(t_info->db_name, db_name);
-    strcpy(t_info->tb_prefix, tb_prefix);
+    tstrncpy(t_info->db_name, db_name, MAX_DB_NAME_SIZE);
+    tstrncpy(t_info->tb_prefix, tb_prefix, MAX_TB_NAME_SIZE);
     t_info->datatype = data_type;
     t_info->ncols_per_record = ncols_per_record;
     t_info->nrecords_per_table = nrecords_per_table;
@@ -1001,9 +1001,9 @@ int32_t generateData(char *res, char **data_type, int num_of_cols, int64_t times
     } else if (strcasecmp(data_type[i % c], "bigint") == 0) {
       pstr += sprintf(pstr, ", %" PRId64, trand() % 2147483648);
     } else if (strcasecmp(data_type[i % c], "float") == 0) {
-      pstr += sprintf(pstr, ", %10.4f", (float)(trand() / 1000));
+      pstr += sprintf(pstr, ", %10.4f", (float)(trand() / 1000.0));
     } else if (strcasecmp(data_type[i % c], "double") == 0) {
-      double t = (double)(trand() / 1000000);
+      double t = (double)(trand() / 1000000.0);
       pstr += sprintf(pstr, ", %20.8f", t);
     } else if (strcasecmp(data_type[i % c], "bool") == 0) {
       bool b = trand() & 1;
diff --git a/src/kit/taosdump/taosdump.c b/src/kit/taosdump/taosdump.c
index 46b14d6e56b5a526a9d84d40735ffe3f6292abcd..dea05e1c2a423d0b794724f8217e2216c7e24807 100644
--- a/src/kit/taosdump/taosdump.c
+++ b/src/kit/taosdump/taosdump.c
@@ -238,7 +238,7 @@ static error_t parse_opt(int key, char *arg, struct argp_state *state) {
         fprintf(stderr, "Invalid path %s\n", arg);
         return -1;
       }
-      strcpy(arguments->input, full_path.we_wordv[0]);
+      tstrncpy(arguments->input, full_path.we_wordv[0], TSDB_FILENAME_LEN);
       wordfree(&full_path);
       break;
     case 'c':
@@ -246,7 +246,7 @@ static error_t parse_opt(int key, char *arg, struct argp_state *state) {
         fprintf(stderr, "Invalid path %s\n", arg);
         return -1;
       }
-      strcpy(configDir, full_path.we_wordv[0]);
+      tstrncpy(configDir, full_path.we_wordv[0], TSDB_FILENAME_LEN);
       wordfree(&full_path);
       break;
     case 'e':
@@ -537,11 +537,11 @@ int taosDumpOut(SDumpArguments *arguments) {
 
   if (arguments->databases || arguments->all_databases) {
     for (int i = 0; i < count; i++) {
-      taosDumpDb(dbInfos[i], arguments, fp);
+      (void)taosDumpDb(dbInfos[i], arguments, fp);
     }
   } else {
     if (arguments->arg_list_len == 1) {
-      taosDumpDb(dbInfos[0], arguments, fp);
+      (void)taosDumpDb(dbInfos[0], arguments, fp);
     } else {
       taosDumpCreateDbClause(dbInfos[0], arguments->with_property, fp);
 
@@ -560,9 +560,9 @@ int taosDumpOut(SDumpArguments *arguments) {
         }
 
         if (tableRecordInfo.isMetric) {  // dump whole metric
-          taosDumpMetric(tableRecordInfo.tableRecord.metric, arguments, fp);
+          (void)taosDumpMetric(tableRecordInfo.tableRecord.metric, arguments, fp);
         } else {  // dump MTable and NTable
-          taosDumpTable(tableRecordInfo.tableRecord.name, tableRecordInfo.tableRecord.metric, arguments, fp);
+          (void)taosDumpTable(tableRecordInfo.tableRecord.name, tableRecordInfo.tableRecord.metric, arguments, fp);
         }
       }
     }
@@ -645,6 +645,7 @@ int taosDumpDb(SDbInfo *dbInfo, SDumpArguments *arguments, FILE *fp) {
   (void)lseek(fd, 0, SEEK_SET);
 
   while (1) {
+    memset(&tableRecord, 0, sizeof(STableRecord));
     ssize_t ret = read(fd, &tableRecord, sizeof(STableRecord));
     if (ret <= 0) break;
     
@@ -654,8 +655,9 @@ int taosDumpDb(SDbInfo *dbInfo, SDumpArguments *arguments, FILE *fp) {
   }
 
   close(fd);
+  remove(".table.tmp");
 
-  return remove(".table.tmp");
+  return 0;
 }
 
 void taosDumpCreateTableClause(STableDef *tableDes, int numOfCols, SDumpArguments *arguments, FILE *fp) {
@@ -877,7 +879,7 @@ int32_t taosDumpMetric(char *metric, SDumpArguments *arguments, FILE *fp) {
   int fd = -1;
   STableRecord tableRecord;
 
-  tstrncpy(tableRecord.metric, metric, TSDB_TABLE_NAME_LEN);
+  //tstrncpy(tableRecord.metric, metric, TSDB_TABLE_NAME_LEN);
 
   sprintf(command, "select tbname from %s", metric);
   TAOS_RES* result = taos_query(taos, command);
@@ -898,8 +900,8 @@ int32_t taosDumpMetric(char *metric, SDumpArguments *arguments, FILE *fp) {
 
   while ((row = taos_fetch_row(result)) != NULL) {
     memset(&tableRecord, 0, sizeof(STableRecord));
-    strncpy(tableRecord.name, (char *)row[0], fields[0].bytes);
-    strcpy(tableRecord.metric, metric);
+    tstrncpy(tableRecord.name, (char *)row[0], fields[0].bytes);
+    tstrncpy(tableRecord.metric, metric, TSDB_TABLE_NAME_LEN);
     twrite(fd, &tableRecord, sizeof(STableRecord));
   }
 
@@ -908,7 +910,8 @@ int32_t taosDumpMetric(char *metric, SDumpArguments *arguments, FILE *fp) {
 
   (void)lseek(fd, 0, SEEK_SET);
 
-  while (1) {
+  while (1) {    
+    memset(&tableRecord, 0, sizeof(STableRecord));
     ssize_t ret = read(fd, &tableRecord, sizeof(STableRecord));
     if (ret <= 0) break;
     
@@ -917,7 +920,7 @@ int32_t taosDumpMetric(char *metric, SDumpArguments *arguments, FILE *fp) {
     taosDumpTable(tableRecord.name, tableRecord.metric, arguments, fp);
   }
 
-  tclose(fd);
+  close(fd);
   (void)remove(".table.tmp");
 
   return 0;
diff --git a/src/os/linux/src/linuxSysPara.c b/src/os/linux/src/linuxSysPara.c
index 31ae33cdfc7c7c71064f3ee21bc690ae57656596..04fa6b1f568d6ae0785d817e8666e86b1373ab6d 100644
--- a/src/os/linux/src/linuxSysPara.c
+++ b/src/os/linux/src/linuxSysPara.c
@@ -162,7 +162,13 @@ static void taosGetSystemTimezone() {
   FILE *f = fopen("/etc/timezone", "r");
   char  buf[65] = {0};
   if (f != NULL) {
-    (void)fread(buf, 64, 1, f);
+    int len = fread(buf, 64, 1, f);
+    if(len < 64 && ferror(f)) {
+      fclose(f);
+      uError("read /etc/timezone error, reason:%s", strerror(errno));
+      return;
+    }
+    
     fclose(f);
   }
 
@@ -547,7 +553,7 @@ 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=%" PRIu64, rlim.rlim_cur, rlim.rlim_max);
+    uPrint("the old unlimited para: rlim_cur=%" PRIu64, ", 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 +565,7 @@ void taosSetCoreDump() {
   }
 
   if (getrlimit(RLIMIT_CORE, &rlim) == 0) {
-    uPrint("the new unlimited para: rlim_cur=%d, rlim_max=%" PRIu64, rlim.rlim_cur, rlim.rlim_max);
+    uPrint("the new unlimited para: rlim_cur=%" PRIu64, ", rlim_max=%" PRIu64, rlim.rlim_cur, rlim.rlim_max);
   }
 
 #ifndef _TD_ARM_
diff --git a/src/util/src/tlog.c b/src/util/src/tlog.c
index 599cf3262b61359b05a71087a3b6ad2dde4139cb..50dae7b1779bbc735749db220b306238480d56fa 100644
--- a/src/util/src/tlog.c
+++ b/src/util/src/tlog.c
@@ -147,7 +147,7 @@ static void *taosThreadToOpenNewFile(void *param) {
     return NULL;
   }
   taosLockFile(fd);
-  lseek(fd, 0, SEEK_SET);
+  (void)lseek(fd, 0, SEEK_SET);
 
   int32_t oldFd = tsLogObj.logHandle->fd;
   tsLogObj.logHandle->fd = fd;
diff --git a/src/util/src/tnote.c b/src/util/src/tnote.c
index 20c77d4fbe14b9f8151abe314e9e1df369931edc..aa618985431155cef80590bb9c4ef618b3be2704 100644
--- a/src/util/src/tnote.c
+++ b/src/util/src/tnote.c
@@ -92,7 +92,7 @@ void *taosThreadToOpenNewNote(void *param)
     }
 
     taosLockNote(fd, pNote);
-    lseek(fd, 0, SEEK_SET);
+    (void)lseek(fd, 0, SEEK_SET);
 
     int oldFd = pNote->taosNoteFd;
     pNote->taosNoteFd = fd;