How to get key names from JSON using jq

You can use:

jq 'keys' file.json

Complete example

$ cat file.json{ "Archiver-Version" : "Plexus Archiver", "Build-Id" : "", "Build-Jdk" : "1.7.0_07", "Build-Number" : "", "Build-Tag" : "", "Built-By" : "cporter", "Created-By" : "Apache Maven", "Implementation-Title" : "northstar", "Implementation-Vendor-Id" : "com.test.testPack", "Implementation-Version" : "testBox", "Manifest-Version" : "1.0", "appname" : "testApp", "build-date" : "02-03-2014-13:41", "version" : "testBox" }$ jq 'keys' file.json[  "Archiver-Version",  "Build-Id",  "Build-Jdk",  "Build-Number",  "Build-Tag",  "Built-By",  "Created-By",  "Implementation-Title",  "Implementation-Vendor-Id",  "Implementation-Version",  "Manifest-Version",  "appname",  "build-date",  "version"]

UPDATE: To create a BASH array using these keys:

Using BASH 4+:

mapfile -t arr < <(jq -r 'keys[]' ms.json)

On older BASH you can do:

arr=()while IFS='' read -r line; do   arr+=("$line")done < <(jq 'keys[]' ms.json)

Then print it:

printf "%s\n" ${arr[@]}"Archiver-Version""Build-Id""Build-Jdk""Build-Number""Build-Tag""Built-By""Created-By""Implementation-Title""Implementation-Vendor-Id""Implementation-Version""Manifest-Version""appname""build-date""version"

You need to use jq 'keys[]'. For example:

echo '{"example1" : 1, "example2" : 2, "example3" : 3}' | jq 'keys[]'

Will output a line separated list:

"example1""example2""example3"

To get the keys on a deeper node in a JSON:

echo '{"data": "1", "user": { "name": 2, "phone": 3 } }' | jq '.user | keys[]'"name""phone"