Shell - jq: Turning json list of `keys.childkeys` into list of lists-CodePudding

I am using jq to parse a json file. This is the current output from jq:

[
 "key1.childk2",
 "key2.childk3"
]

I would like to turn this into a readable json format itself as list of lists like below:

    [ 
      ["key1","childk2"],
      ["key2","childk3"]
    ]

I would ideally prefer to do this with jq, however any other shell tool that can work on shell variables is fair game.

CodePudding user response：

You can use jq split filter:

jq '[.[] | split(".")]'

[
  [
    "key1",
    "childk2"
  ],
  [
    "key2",
    "childk3"
  ]
]

You should use it somewhere in the original jq command

CodePudding user response：

Here is a ruby to do that:

ruby -r json -e 'puts JSON.parse($<.read).map{|e| e.split(".")}.to_json' file

[["key1","childk2"],["key2","childk3"]]

Or if you want it pretty:

ruby -r json -e 'puts JSON.pretty_generate(
            JSON.parse($<.read).map{|e| e.split(".")})
' file
[
  [
    "key1",
    "childk2"
  ],
  [
    "key2",
    "childk3"
  ]
]

Or you can produce your precise format:

ruby -r json -e '
l=[]
JSON.parse($<.read).map{|e| l << e.split(".").to_s}
puts "[\n\t#{l.join(",\n\t")}\n]"
' file 
[
    ["key1", "childk2"],
    ["key2", "childk3"]
]

CodePudding user response：

With jq you can structurally turn the input into your desired JSON document using simple filters like map(./"."), but regarding the requested readability, the output wouldn't be exactly in your desired formatting.

Without any further flags, jq would pretty-print the output as:

[
  [
    "key1",
    "childk2"
  ],
  [
    "key2",
    "childk3"
  ]
]

Demo

Using the --compact-output or -c flag would compress the whole JSON document into one line, not just the elements of the outer array:

[["key1","childk2"],["key2","childk3"]]

Demo

So, if you really wanted to, you could also glue together the parts yourself as you like them to be formatted from within jq, but honestly, I would discourage you from doing so as by circumventing jq's JSON composer you might end up outputting invalid JSON.

jq -r '"[", "  "   ([.[] / "." | tojson] | .[:-1][]  = ",")[], "]"'

[
  ["key1","childk2"],
  ["key2","childk3"]
]

Demo