If statement in launch file

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I want to cancel the creation of a node in the launch file if a value, which is entered by user in console, equals a certain value. For instance

I am launching a file: roslaunch file attr1:='1' attr2:='2'

and in my launch file i want to do a check. the syntax in any other language would be :

if (attr1 == value){ cancel node};

problem is, in the launch file I tried to use a unless="$(arg attr1)" but it's not a bool because when i enter the value in the console, it is an int. So i realized the unless and if conditionals in the launch file are explicitly looking for a true or false, and that they can't do a comparison:

unless="$(arg attr1 == '1')"

did not work. any suggestions? Any syntax I can use launch file that would make this work?

THANKS!