Time stamp not getting updated and does not have nsecs in Topic Subscriber

[gtatiya]

Hi,

I want to record all the data from /gripper/joint_states topic. But, the value for /gripper/joint_states/header/stamp key does not change and does not have nsecs. I am using this to print the data:

printf("--------- %s ----------\n", topic_name.c_str());
  for (auto it : deserialized_msg->renamed_vals)
  {
    const std::string& key = it.first;
    double value = it.second;
    std::cout << key << " = " << value << std::endl;
  }
  for (auto it : deserialized_msg->flat_msg.name)
  {
    const std::string& key = it.first.toStdString();
    const std::string& value = it.second;
    std::cout << key << " = " << value << std::endl;
  }

The output is:

--------- /gripper/joint_states ----------
/gripper/joint_states/header/seq = 2092
/gripper/joint_states/header/stamp = 1.66437e+09
/gripper/joint_states/position.0 = 0.785903
/gripper/joint_states/velocity.0 = 0
/gripper/joint_states/header/frame_id = 
/gripper/joint_states/name.0 = gripper_finger1_joint
--------- /gripper/joint_states ----------
/gripper/joint_states/header/seq = 2093
/gripper/joint_states/header/stamp = 1.66437e+09
/gripper/joint_states/position.0 = 0.785903
/gripper/joint_states/velocity.0 = 0
/gripper/joint_states/header/frame_id = 
/gripper/joint_states/name.0 = gripper_finger1_joint

But, when I run rostopic echo /gripper/joint_states, I get this output:

header: 
  seq: 37982
  stamp: 
    secs: 1664374975
    nsecs: 506310939
  frame_id: ''
name: [gripper_finger1_joint]
position: [0.0]
velocity: [0.0]
effort: []
---
header: 
  seq: 37983
  stamp: 
    secs: 1664374975
    nsecs: 538561105
  frame_id: ''
name: [gripper_finger1_joint]
position: [0.0]
velocity: [0.0]
effort: []

secs changes after each second and nsecs also changes for each message, but by using ros_msg_parser I can't get the updated time stamp. Could you please help?