Want to launch another launch file when the first launch file is closed

edit

Hi everyone, this is my first time posting on an online forum for answer, so please bear with me.

As the title suggests, when a node is killed, I want the launch file to launch (possibly) the same launch file again, using the RegisterEventHandler action, here is my code for now.

lifecycle_launch.py

def generate_launch_description():

life_node = LifecycleNode(package='lifecycle', executable='lifecycle_talker',
                  name='lc_talker', namespace='', output='screen')

def launch_setup(context, *args, **kwargs):
    return [ ExecuteProcess(
        cmd=[[
            'ros2 launch lifecycle_py test_launch.py'
        ]], shell=True
    ),
    ]

return LaunchDescription([
    life_node,
    RegisterEventHandler(
        OnShutdown(
            on_shutdown=[
                LogInfo(msg='reaches here'),
                OpaqueFunction(function= launch_setup)
            ]
        )
    ), ])

when the program is running and I interrupt using a Ctrl+C, here is the terminal output that I get

 [INFO] [launch]: All log files can be found below /home/amongsus/.ros/log/2023-06-01-10-10-27-092501-computer0-96952
 [INFO] [launch]: Default logging verbosity is set to INFO
 [INFO] [lifecycle_talker-1]: process started with pid [96966]
 ^C[WARNING] [launch]: user interrupted with ctrl-c (SIGINT)
 [INFO] [launch.user]: reaches here
[lifecycle_talker-1] [INFO] [1685628630.993959613] [rclcpp]: signal_handler(signum=2)
[INFO] [lifecycle_talker-1]: process has finished cleanly [pid 96966]

when I do a

ros2 node list

I don't get any output meaning the lauch file wasn't launched. When I replace OnShutdown with OnProcessExit the results are on different, ie. I don't get another launch file. However OnProcessStartdoes indeed launch the file, but it closes as soon as I do a Ctrl+C, on the window meant for lifecycle_launch.py.

Here is the file test_launch.py if that is relevant.

from launch import LaunchDescription
from launch_ros.actions import LifecycleNode
from launch_ros.actions import Node
from launch.event_handlers import (OnExecutionComplete, OnProcessExit,
                                OnProcessIO, OnProcessStart, OnShutdown)
from launch.events import Shutdown
from launch.actions import (DeclareLaunchArgument, EmitEvent, ExecuteProcess,
                            LogInfo, RegisterEventHandler, TimerAction, OpaqueFunction)




def generate_launch_description():

    life_node = LifecycleNode(package='lifecycle', executable='lifecycle_talker',
                    name='lc_talker_1', namespace='', output='screen')

    return LaunchDescription([
        life_node
])

System specs:- Ubuntu 20.04