# Revision history [back]

Hi, I think the easiest way is by defining an arg. Something like:

<arg name="var"/>


and then grouping the nodes to start. Like:

<launch>

Hi, I think the easiest way is by defining an arg. Something like:

<arg name="var"/>


and then grouping the nodes to start. Like:start if the argument of var is true. Your launch file should look like:

<launch>
<arg name="var"/>

<group if="$(arg var)"> ...nodes to start... </group> </launch>  <launch>You can then start the nodes from the terminal with: roslaunch you_package your_node var:=true  Let me know if that helps Hi, I think the easiest way is by defining an arg. Something like: <arg name="var"/>  and then grouping the nodes to start if the argument of var is true. Your launch file should look like: <launch> <arg name="var"/> <group if="$(arg var)">
...nodes to start...
</group>
</launch>


You can then start the nodes from the terminal with:

roslaunch you_package your_node launch_file var:=true


Let me know if that helps