Not able to parse the json using jq

Question

I have following json with me ( file name sample.json)-

{ "Prefix": "pg",
"fileFormat": "gz",
"additionalInfo": " {\\"pgUsername\\":\\"postgres\\",\\"pgPassword\\":\\"postgres\\",\\"pgHostname\\":\\"pgmaster\\"}"
}

I am reading these parameters using follwoing command-
cat sample.json | jq -r '.additionalInfo .pgPassword'

expected output is postgres , but I am getting something like [26]

I cant change this json. Does anyone knows, what command should be used to get correct output? Thanks in advance.

Answer 1

Thanks to fromjson , there's no need to invoke jq twice:

jq -r '.additionalInfo|fromjson|.pgPassword' data.json
postgres

Answer 2

Your json is incorrect (you can verify in on https://jsonlint.com ), you can try this one:

{
    "additionalInfo": {
        "pgUsername": "postgres",
        "pgPassword": "postgres",
        "pgHostname": "pgmaster"
    }
}

And you will get expected result:

$ cat data.json| jq -r '.additionalInfo .pgPassword'
postgres

---

EDIT

For your modified data you can use:

$ cat data.json| jq -r '.additionalInfo' | jq '.pgPassword'
postgres

---

EDIT AGAIN

Please, see a comment by @peak -- it doesn't require multiple execution of jq , instead he proposes to use fromjson builtin.