What are good CLI tools for JSON?

Question

General Problem

Though I may be diagnosing the root cause of an event, determining how many users it affected, or distilling timing logs in order to assess the perform

Answer 1

Fortunately in XML-land, we have wonderful technologies like XPath, XQuery, and XSLT to help us.
[...]
So this leads me to my question: are there any tools like this for JSON?

If you ask me, Xidel is exactly what you're looking for.

Xidel is a command line tool to download and extract data from HTML/XML pages or JSON-APIs, using CSS, XPath 3.0, XQuery 3.0, JSONiq or pattern templates. It can also create new or transformed XML/HTML/JSON documents.

Query:

xidel -s "input.json" \
-e '
  $json/avg(
    count(
      (phoneNumber)()
    )
  )
'

or

xidel -s "input.json" -e '$json/avg(count((phoneNumber)()))'

Output:

2