determine scanf return value.

src/kit/shell/src/shellDarwin.c

@@ -86,7 +86,9 @@ void shellParseArgument(int argc, char *argv[], SShellArguments *arguments) {
         printf(DARWINCLIENT_VERSION, tsOsName, taos_get_client_info());
         if (strlen(argv[i]) == 2) {
             printf("Enter password: ");
-            scanf("%s", g_password);
+            if (scanf("%s", g_password) > 1) {
+                fprintf(stderr, "password read error\n");
+            }
             getchar();
         } else {
             tstrncpy(g_password, (char *)(argv[i] + 2), MAX_PASSWORD_SIZE);

src/kit/shell/src/shellLinux.c

@@ -170,7 +170,9 @@ static void parse_password(
             printf(LINUXCLIENT_VERSION, tsOsName, taos_get_client_info());
             if (strlen(argv[i]) == 2) {
                 printf("Enter password: ");
-                scanf("%s", g_password);
+                if (scanf("%20s", g_password) > 1) {
+                    fprintf(stderr, "password reading error\n");
+                }
                 getchar();
             } else {
                 tstrncpy(g_password, (char *)(argv[i] + 2), MAX_PASSWORD_SIZE);

src/kit/shell/src/shellWindows.c

@@ -84,7 +84,9 @@ void shellParseArgument(int argc, char *argv[], SShellArguments *arguments) {
         printf(WINCLIENT_VERSION, tsOsName, taos_get_client_info());
         if (strlen(argv[i]) == 2) {
             printf("Enter password: ");
-            scanf("%s", g_password);
+            if (scanf("%s", g_password) > 1) {
+                fprintf(stderr, "password read error!\n");
+            }
             getchar();
         } else {
             tstrncpy(g_password, (char *)(argv[i] + 2), MAX_PASSWORD_SIZE);

src/kit/taosdemo/taosdemo.c

@@ -863,7 +863,9 @@ static void parse_args(int argc, char *argv[], SArguments *arguments) {
         } else if (strncmp(argv[i], "-p", 2) == 0) {
             if (strlen(argv[i]) == 2) {
                 printf("Enter password:");
-                scanf("%s", arguments->password);
+                if (scanf("%s", arguments->password) > 1) {
+                    fprintf(stderr, "password read error!\n");
+                }
             } else {
                 tstrncpy(arguments->password, (char *)(argv[i] + 2), MAX_PASSWORD_SIZE);
             }

src/kit/taosdump/taosdump.c

@@ -561,7 +561,9 @@ static void parse_password(
         if (strncmp(argv[i], "-p", 2) == 0) {
             if (strlen(argv[i]) == 2) {
                 printf("Enter password: ");
-                scanf("%s", arguments->password);
+                if(scanf("%20s", arguments->password) > 1) {
+                    errorPrint("%s() LN%d, password read error!\n", __func__, __LINE__);
+                }
             } else {
                 tstrncpy(arguments->password, (char *)(argv[i] + 2), MAX_PASSWORD_SIZE);
             }