Revision history [back]

Sounds like you're looking for the ExecuteProcess Launch action:

from launch import LaunchDescription
from launch.action import ExecuteProcess

def generate_launch_description():
    return LaunchDescription([
        ExecuteProcess(cmd=['ros2', 'topic', 'pub', '--once', /S0',
                            'std_msgs/msg/Float64, '{data: 1.5}']),
        ExecuteProcess(cmd=['ros2', 'topic', 'pub', '--once', /S1',
                            'std_msgs/msg/Float64, '{data: 1.5}']),
    ])

Another example can be found in the launch examples: https://github.com/ros2/launch/blob/master/launch/examples/launch_counters.py#L112

Sounds like you're looking for the ExecuteProcess Launch action:

from launch import LaunchDescription
from launch.action import ExecuteProcess

def generate_launch_description():
    return LaunchDescription([
        ExecuteProcess(cmd=['ros2', 'topic', 'pub', '--once', /S0',
'/S0',
 'std_msgs/msg/Float64, 'std_msgs/msg/Float64', '{data: 1.5}']),
        ExecuteProcess(cmd=['ros2', 'topic', 'pub', '--once', /S1',
'/S1',
 'std_msgs/msg/Float64, 'std_msgs/msg/Float64', '{data: 1.5}']),
    ])

Another example can be found in the launch examples: https://github.com/ros2/launch/blob/master/launch/examples/launch_counters.py#L112