How to stringify JSON using JQ

Question

Using JQ I would like to take a complex JSON object that includes JSON embedded as strings and then turn it all into a valid string I can easily embed in other JSON objects.

For example, lets say I have this json object:

{
  "region": "CA",
  "waf_rule_tags": "{\"RULEID:942100\":[\"application-multi\",\"language-multi\",\"platform-multi\",\"attack-sqli\",\"OWASP_CRS/WEB_ATTACK/SQL_INJECTION\",\"WASCTC/WASC-19\",\"OWASP_TOP_10/A1\",\"OWASP_AppSensor/CIE1\",\"PCI/6.5.2\"]}"
}

I need to turn this all into the following string:

"{\"region\": \"CA\",\"waf_rule_tags\": \"{\\\"RULEID:942100\\\":[\\\"application-multi\\\",\\\"language-multi\\\",\\\"platform-multi\\\",\\\"attack-sqli\\\",\\\"OWASP_CRS/WEB_ATTACK/SQL_INJECTION\\\",\\\"WASCTC/WASC-19\\\",\\\"OWASP_TOP_10/A1\\\",\\\"OWASP_AppSensor/CIE1\\\",\\\"PCI/6.5.2\\\"]}\"}"

That way I can take this string and insert it exactly under the text field of another JSON object to create the following.

{
      "title": "12345-accesslogs",
      "text": "{\"region\": \"CA\",\"waf_rule_tags\": \"{\\\"RULEID:942100\\\":[\\\"application-multi\\\",\\\"language-multi\\\",\\\"platform-multi\\\",\\\"attack-sqli\\\",\\\"OWASP_CRS/WEB_ATTACK/SQL_INJECTION\\\",\\\"WASCTC/WASC-19\\\",\\\"OWASP_TOP_10/A1\\\",\\\"OWASP_AppSensor/CIE1\\\",\\\"PCI/6.5.2\\\"]}\"}",
      "priority": "normal",
      "tags": ["environment:test"],
      "alert_type": "info"
}

peak · Accepted Answer · 2020-04-29T02:59:32.713

12

In brief, tostring is your friend.

Assuming that your original JSON object is in a file named object.json, and that the template is in template.json, you could write:

jq --argfile object object.json '.text = ($object | tostring)' template.json

Needless to say, there are numerous variations on this theme, e.g.

jq -n 'input | input + {text: tostring}' \
   object.json template.json

or more compactly if slightly more obscurely:

jq 'input + {text: tostring}' object.json template.json

edited Apr 29 '20 at 02:59

answered Apr 29 '20 at 01:32

peak

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Yep `jq '.| tostring' my_file.json` was what I was looking for. – Alex Cohen Apr 29 '20 at 02:24
6

You can simply write: `jq tostring my_file.json` :-) – peak Apr 29 '20 at 02:56

score 8 · Answer 2 · edited Jul 28 '23 at 13:59

8

I found @peak's comment in their own answer so useful I wanted to make it an answer on its own:

$ echo '{ "foo": [ "bar", "baz" ] }' | jq -r tostring
{\"foo\":[\"bar\",\"baz\"]}

edited Jul 28 '23 at 13:59

marverix

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answered Jul 17 '21 at 09:44

Jon Lauridsen

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score 3 · Answer 3 · answered May 19 '22 at 05:38

JQ provides tojson and fromjson filters for that.

Note about the answers proposing tostring: The JQ manual says about tojson:

The tojson builtin differs from tostring in that tostring returns strings unmodified, while tojson encodes strings as JSON strings.

So I think tojson is always correct but tostring is only correct as long as you only use complex objects.

phhu · Answer 4 · 2022-05-20T09:04:54.637

1

A variation on this is to stringify a given key within a JSON structure using tostring something like this:

echo '{"a":1,"b":{"c":{"d":2},"e":3}}' | jq '.b.c=(.b.c|tostring)'

...which targets path b.c to give:

{
  "a": 1,
  "b": {
    "c": "{\"d\":2}",
    "e": 3
  }
}

(As per A.H.'s answer, tojson might be useful instead of tostring if you want strings to be json-string-encoded as well)

edited May 20 '22 at 09:04

answered May 18 '22 at 21:54

phhu

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How to stringify JSON using JQ

4 Answers4