diff --git a/docs/examples/c/tmq_demo.c b/docs/examples/c/tmq_demo.c
index 30cbbdc1c0..6277d61b8a 100644
--- a/docs/examples/c/tmq_demo.c
+++ b/docs/examples/c/tmq_demo.c
@@ -13,6 +13,8 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
+// to compile: gcc -o tmq_demo tmq_demo.c -ltaos -lpthread
+
 #include <assert.h>
 #include <pthread.h>
 #include <stdio.h>
@@ -33,9 +35,9 @@ void* prepare_data(void* arg) {
   uint16_t    port      = 6030;
   TAOS *pConn = taos_connect(host, user, password, NULL, port);
   if (pConn == NULL) {
-    printf("Failed to connect to %s:%hu; ErrCode: 0x%x; ErrMessage: %s.\n", host, port, taos_errno(NULL), taos_errstr(NULL));
+    fprintf(stderr, "Failed to connect to %s:%hu; ErrCode: 0x%x; ErrMessage: %s.\n", host, port, taos_errno(NULL), taos_errstr(NULL));
     taos_cleanup();
-    return -1;
+    return NULL;
   }
 
   TAOS_RES* pRes;
@@ -52,12 +54,12 @@ void* prepare_data(void* arg) {
 
     pRes = taos_query(pConn, buf);
     if (taos_errno(pRes) != 0) {
-      printf("Failed to insert data to power.meters, reason: %s\n", taos_errstr(pRes));
+      fprintf(stderr, "Failed to insert data to power.meters, reason: %s\n", taos_errstr(pRes));
     }
     taos_free_result(pRes);
     sleep(1);
   }
-  printf("Prepare data thread exit\n");
+  fprintf(stdout, "Prepare data thread exit\n");
   return NULL;
 }
 
@@ -69,9 +71,9 @@ static int32_t msg_process(TAOS_RES* msg) {
   const char* dbName = tmq_get_db_name(msg);
   int32_t     vgroupId = tmq_get_vgroup_id(msg);
 
-  printf("topic: %s\n", topicName);
-  printf("db: %s\n", dbName);
-  printf("vgroup id: %d\n", vgroupId);
+  fprintf(stdout, "topic: %s\n", topicName);
+  fprintf(stdout, "db: %s\n", dbName);
+  fprintf(stdout, "vgroup id: %d\n", vgroupId);
 
   while (1) {
     // get one row data from message
@@ -87,11 +89,11 @@ static int32_t msg_process(TAOS_RES* msg) {
     rows++;
     // print the row content
     if (taos_print_row(buf, row, fields, numOfFields) < 0) {
-      printf("Failed to print row\n");
+      fprintf(stderr, "Failed to print row\n");
       break;
     }
     // print the precision and row content to the console
-    printf("precision: %d, row content: %s\n", precision, buf);
+    fprintf(stdout, "precision: %d, data: %s\n", precision, buf);
   }
 
   return rows;
@@ -105,42 +107,42 @@ static int32_t init_env() {
   uint16_t    port      = 6030;
   TAOS *pConn = taos_connect(host, user, password, NULL, port);
   if (pConn == NULL) {
-    printf("Failed to connect to %s:%hu; ErrCode: 0x%x; ErrMessage: %s.\n", host, port, taos_errno(NULL), taos_errstr(NULL));
+    fprintf(stderr, "Failed to connect to %s:%hu; ErrCode: 0x%x; ErrMessage: %s.\n", host, port, taos_errno(NULL), taos_errstr(NULL));
     taos_cleanup();
     return -1;
   }
 
   TAOS_RES* pRes;
   // drop database if exists
-  printf("create database\n");
+  fprintf(stdout, "Create database.\n");
   pRes = taos_query(pConn, "drop topic if exists topic_meters");
   if (taos_errno(pRes) != 0) {
-    printf("error in drop topic_meters, reason:%s\n", taos_errstr(pRes));
+    fprintf(stderr, "Failed to drop topic_meters, reason:%s\n", taos_errstr(pRes));
   }
   taos_free_result(pRes);
 
   pRes = taos_query(pConn, "drop database if exists power");
   if (taos_errno(pRes) != 0) {
-    printf("error in drop power, reason:%s\n", taos_errstr(pRes));
+    fprintf(stderr, "Failed to drop database power, reason:%s\n", taos_errstr(pRes));
   }
   taos_free_result(pRes);
 
   // create database
   pRes = taos_query(pConn, "create database power precision 'ms' WAL_RETENTION_PERIOD 3600");
   if (taos_errno(pRes) != 0) {
-    printf("error in create tmqdb, reason:%s\n", taos_errstr(pRes));
+    fprintf(stderr, "Failed to create tmqdb, reason:%s\n", taos_errstr(pRes));
     goto END;
   }
   taos_free_result(pRes);
 
   // create super table
-  printf("create super table\n");
+  fprintf(stdout, "Create super table.\n");
   pRes = taos_query(
       pConn,
       "CREATE STABLE IF NOT EXISTS power.meters (ts TIMESTAMP, current FLOAT, voltage INT, phase FLOAT) TAGS "
       "(groupId INT, location BINARY(24))");
   if (taos_errno(pRes) != 0) {
-    printf("failed to create super table meters, reason:%s\n", taos_errstr(pRes));
+    fprintf(stderr, "Failed to create super table meters, reason:%s\n", taos_errstr(pRes));
     goto END;
   }
 
@@ -155,7 +157,7 @@ END:
 }
 
 int32_t create_topic() {
-  printf("create topic\n");
+  fprintf(stdout, "Create topic.\n");
   TAOS_RES* pRes;
   const char *host      = "localhost";
   const char *user      = "root";
@@ -163,14 +165,14 @@ int32_t create_topic() {
   uint16_t    port      = 6030;
   TAOS *pConn = taos_connect(host, user, password, NULL, port);
   if (pConn == NULL) {
-    printf("Failed to connect to %s:%hu; ErrCode: 0x%x; ErrMessage: %s.\n", host, port, taos_errno(NULL), taos_errstr(NULL));
+    fprintf(stderr, "Failed to connect to %s:%hu; ErrCode: 0x%x; ErrMessage: %s.\n", host, port, taos_errno(NULL), taos_errstr(NULL));
     taos_cleanup();
     return -1;
   }
 
   pRes = taos_query(pConn, "use power");
   if (taos_errno(pRes) != 0) {
-    printf("error in use tmqdb, reason:%s\n", taos_errstr(pRes));
+    fprintf(stderr, "Failed to use tmqdb, reason:%s\n", taos_errstr(pRes));
     return -1;
   }
   taos_free_result(pRes);
@@ -179,7 +181,7 @@ int32_t create_topic() {
       pConn,
       "CREATE TOPIC IF NOT EXISTS topic_meters AS SELECT ts, current, voltage, phase, groupid, location FROM meters");
   if (taos_errno(pRes) != 0) {
-    printf("failed to create topic topic_meters, reason:%s\n", taos_errstr(pRes));
+    fprintf(stderr, "Failed to create topic topic_meters, reason:%s\n", taos_errstr(pRes));
     return -1;
   }
   taos_free_result(pRes);
@@ -189,7 +191,7 @@ int32_t create_topic() {
 }
 
 void tmq_commit_cb_print(tmq_t* tmq, int32_t code, void* param) {
-  printf("tmq_commit_cb_print() code: %d, tmq: %p, param: %p\n", code, tmq, param);
+  fprintf(stdout, "tmq_commit_cb_print() code: %d, tmq: %p, param: %p\n", code, tmq, param);
 }
 
 // ANCHOR: create_consumer_1
@@ -261,6 +263,7 @@ tmq_list_t* build_topic_list() {
   if (code) {
     // if failed, destroy the list and return NULL
     tmq_list_destroy(topicList);
+    fprintf(stderr, "Failed to create topic_list, ErrCode: 0x%x; ErrMessage: %s.\n", code, tmq_err2str(code));
     return NULL;
   }
   // if success, return the list
@@ -313,7 +316,9 @@ void consume_repeatly(tmq_t* tmq) {
 
     code = tmq_offset_seek(tmq, topic_name, p->vgId, p->begin);
     if (code != 0) {
-      fprintf(stderr, "Failed to seek to %d, reason:%s", (int)p->begin, tmq_err2str(code));
+      fprintf(stderr, "Failed to seek assignment %d to beginning %ld, reason: %s.\n", i, p->begin, tmq_err2str(code));
+    } else {
+      fprintf(stdout, "Seek assignment %d to beginning %ld successfully.\n", i, p->begin);
     }
   }
 
@@ -347,7 +352,7 @@ void manual_commit(tmq_t* tmq) {
         taos_free_result(tmqmsg);
         break;
       } else {
-        printf("Commit offset manually successfully.");
+        fprintf(stdout, "Commit offset manually successfully.");
       }
       // free the message
       taos_free_result(tmqmsg);
@@ -386,20 +391,21 @@ int main(int argc, char* argv[]) {
     fprintf(stderr, "Failed to create consumer.\n");
     return -1;
   }
-  printf("Create consumer successfully.\n");
+  fprintf(stdout, "Create consumer successfully.\n");
 
   // ANCHOR_END: create_consumer_2
 
   // ANCHOR: subscribe_3
   tmq_list_t* topic_list = build_topic_list();
   if (NULL == topic_list) {
+    fprintf(stderr, "Failed to create topic_list.\n");
     return -1;
   }
 
   if ((code = tmq_subscribe(tmq, topic_list))) {
-    fprintf(stderr, "Failed to tmq_subscribe(): %s\n", tmq_err2str(code));
+    fprintf(stderr, "Failed to subscribe tmq_subscribe(): %s\n", tmq_err2str(code));
   } else {
-    printf("Subscribe topics successfully.\n");
+    fprintf(stdout, "Subscribe topics successfully.\n");
   }
 
   tmq_list_destroy(topic_list);