Print message from launch file

edit

I don't think it's possible to print text directly form the roslaunch xml (w/o passing it into a node as a param / arg).

Best solution would be to put

print("Please keep this running in a separate tab.")

in your node script.

In your *.launch script, if you set the node's output attribute to "screen", the message will be printed to the terminal window.

<node name="PrintToScreenNode_1" pkg="my_package" type="print_to_screen.py" output="screen"/>

Note: You can also start your nodes in their own separate terminal windows using the launch-prefix attribute.

<node name="PrintToScreenNode_2" pkg="my_package" type="print_to_screen.py" output="screen" launch-prefix="xterm -e"/>

EDIT:

Here's an example script that just prints to the terminal:

#!/usr/bin/env python
# -*- coding: utf-8 -*-

'''
# Name: print_to_screen.py
# Author: Joseph Coombe
'''

# Uncomment lines 10, 13, 15 if you're running this node in its own separate
# terminal window. Otherwise the script will immediately exit and its terminal window will close.
#import rospy

def main():
    #rospy.init_node('print_to_screen', anonymous=True)
    print("Please keep this running in a separate tab.")
    #rospy.spin()

if __name__ == '__main__':
    main()

You'll want to un-comment the rospy lines if you're launching this script in its own terminal (by using the launch-prefix attribute in your *.launch file). Otherwise, it'll immediately exit and close its terminal window (and as a result nobody will see the message).