Let's say I have a JSON file representing a bunch of people's reading lists.
That means it is an array of objects where each object is a person's reading
profile and contains a list of books. Some of those books have a status of
reading meaning the person is currently reading that book.
How can we find all books that are currently being read?
jq '. | map(
{
name: .username,
in_progress_books: (.books | map(select(.status == "reading")))
}
)'
[
{ name: 'bobr', in_progress_books: [...] },
{ name: 'sallyf', in_progress_books: [...] },
...
]
That will show us for each reader what books they are currently reading.
Alternatively, we could roll that all up into a single list of books.
jq '. |
map(.books | map(select(.status == "reading"))) |
flatten'
[
{ title: 'Moby Dick', status: 'reading', ... }
{ title: 'The Great Gatsby', status: 'reading', ... }
...
]