Feb 24, 2024


Great tool for filtering, formatting, and outputting json.

A bit cryptic though.

jq appears to be largely unmaintained at this point, which is sad

cat some.json | jq -r '(map(keys) | add | unique) as $cols | map(. as $row | $cols | map($row[.])) as $rows | $cols, $rows[] | @csv'

JBOL is a collection of jq modules you can install. this is an example of some of the powerful stuff you can do with jq, I understand very little of it

Find every package.json file in a monorepo (using fd), and update the react version in dependencies or in peerDependencies, if it exists:

#!/usr/bin/env bash
# update react in all package.json files
# To install dependencies on a mac:
# brew install fd jq sponge

dep='if .dependencies.react != null then .dependencies.react = "^18.2.0" else . end'
depDom='if .dependencies."react-dom" != null then .dependencies."react-dom" = "^18.2.0" else . end'
peerDep='if .peerDependencies.react != null then .peerDependencies.react = "18.x" else . end'
peerDepDom='if .peerDependencies."react-dom" != null then .peerDependencies."react-dom" = "18.x" else . end'

for p in $(fd package.json --exclude bower_components); do
    jq "$dep" "$p" | 
        jq "$depDom" | 
        jq "$peerDep" | 
        jq "$peerDepDom" | 
        sponge "$p"

Turn a folder full of json files, each of which contains an array of objects, into a single array of objects, and output it to a file:

jq -n '[inputs.[]]' lists/*.json > one_big_list.json

uses the inputs special variable

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