pfBlockerNG-devel includes the jq json parsing application.

You can use that tool to slice and dice JSON files into a list of IPs.

See: Get Microsoft URLs, IP addresses and Ports

For Example

Download the file:

fetch -o /tmp/o365 "https://endpoints.office.com/endpoints/worldwide?noipv6&ClientRequestId=b10c5ed1-bad1-445f-b386-b919946339a7"

List all O365 ServiceAreas:

jq -r '.[].serviceArea' /tmp/o365 | sort | uniq

returns:

Common
Exchange
SharePoint
Skype

Collect all IPs for the Exchange Service Area and aggregate the IPs using iprange:

jq -r '.[] | select(.serviceArea=="Exchange") | select(.ips) .ips[]' /tmp/o365 | iprange