JSON to jq paths or XML xpath

Purpose

To get insight into the structure of arbitrary JSON files from the command line. Provides building blocks for further processing both with 'jq' as well as other tools intended to be used with XML xpath.

Requirements

• jq installed see https://github.com/stedolan/jq/ (Most likely installs with your package manager.)

• the one liner jq scripts this ropo is for

Usage

Snagging a random (to me) test JSON file from a neat looking awk json parser project

curl -sL https://github.com/step-/JSON.awk/raw/master/test-cases/20170131-issue-007-test.json > testdata.json

Result from generating jq paths

 ./json2jqpath.jq testdata.json > testdata.jqpath

Note: making up the format suffix .jqpath

cat testdata.jqpath
.
.response
.response|.count
.response|.data
.response|.data|.[]
.response|.data|.[]|.person
.response|.data|.[]|.person|.address
.response|.data|.[]|.person|.age
.response|.data|.[]|.person|.balance
.response|.data|.[]|.person|.company
.response|.data|.[]|.person|.coords
.response|.data|.[]|.person|.coords|.lat
.response|.data|.[]|.person|.coords|.long
.response|.data|.[]|.person|.email
.response|.data|.[]|.person|.gender
.response|.data|.[]|.person|.guid
.response|.data|.[]|.person|.id
.response|.data|.[]|.person|.isActive
.response|.data|.[]|.person|.name
.response|.data|.[]|.person|.phone
.response|.data|.[]|.person|.picture
.response|.data|.[]|.person|.registered
.response|.data|.[]|.person|.tags
.response|.data|.[]|.person|.tags|.[]
.response|.pagecount

This is a succinct representation of every simple path available through the json structure.

Example: To see what the distribution of most common tags in that file.

Noting that the path agrument to the next jq call
".response|.data|.[]|.person|.tags|.[]"
is cut-n-paste from the next to last line of output from json2jqpath.jq above.

jq ".response|.data|.[]|.person|.tags|.[]" testdata.json |
    sort | uniq -c | sort -nr | head
     75 "est"
     64 "labore"
     63 "consectetur"
     58 "occaecat"
     57 "fugiat"
     57 "excepteur"
     56 "proident"
     56 "Lorem"
     56 "laborum"
     56 "incididunt"

Looks like they used Lorem Ipsum as filler.

Try for something more specific such as person's name and location.

jq ".response|.data|.[]|.person|.name,.coords" testdata.json | head
"Anastasia Goodwin"
{
  "lat": 71.050828,
  "long": 113.565478
}
"Peters Watson"
{
  "lat": 0.203464,
  "long": -71.896296
}

Result for genreating XML xpaths

./json2xpath.jq testdata.json| sort -u > testdata.xpath
cat testdata.xpath
./response
./response/count
./response/data
./response/data/person
./response/data/person/address
./response/data/person/age
./response/data/person/balance
./response/data/person/company
./response/data/person/coords
./response/data/person/coords/lat
./response/data/person/coords/long
./response/data/person/email
./response/data/person/gender
./response/dfromata/person/guid
./response/data/person/id
./response/data/person/isActive
./response/data/person/name
./response/data/person/phone
./response/data/person/picture
./response/data/person/registered
./response/data/person/tags
./response/pagecount

which is a good starting point for tools such as xpath2dot.awk

./json2xpath.jq testdata.json |
    sort -u |
    xpath2dot.awk -v ORIENT="UD" |
    dot -T svg > testdata.svg

---

A note on the use of sort -u above

The script json2xpath.jq has the ability to sort and remove duplicates but they are commented out.

They are disabled by default to allow more use cases for example:

• We may be extracting data in some other program & want to know the native order
• We may be interested in counts of things of various types

If you know these are not your use case you can uncomment them in the script and eliminate piping the output through sort -u