JQ def / helper functions example
Define reusable helper functions in jq with def. Interactive example showing how to declare a function and apply it inside a pipeline.
The jq expression
def name: body; declares a reusable jq function that you can call later in the pipeline, which keeps complex filters readable. Here we define isLocalhost to test whether a value equals "127.0.0.1", then apply it to each host to flag which ones are localhost.
