JSON

JSON is the “Javascript Object Notation”, basically a file format for
data that’s suitable for easy processing by most modern web-based tools.

Several tilde.club programs expose APIs essentially by spitting out JSON
as their output, including e.g. the list of recently updated home pages
at

http://tilde.club/~delfuego/tilde.24h.json[1]

If you’re looking to parse JSON from the command line with a minimum of
code, the jq program may be your thing. jq is a filter that takes JSON
on standard input and produces JSON on standard output. Along the way in
the middle you can do various standard sorts of file munging on a field
by field basis.

Documentation for jq is in its manual.[2]

[1] http://tilde.club/~delfuego/tilde.24h.json

[2] http://stedolan.github.io/jq/manual/