jq read .txt file and write the values to json file

Question

I want to use jq to parse a .txt file with a list of country codes and write them to the value in a JSON object.

Here is what I have so far:

cat myfile.json | 
jq -R -f test_id.txt 'select(.country == []).country = "test_id.txt"' > newfile.json

Where .txt file looks like this:

"NSC"
"KZC"
"KCC"
"KZL"
"NZG"
"VRU"
"ESM"
"KZF"
"SFU"
"EWF"
"KQY"
"KQV"

and my JSON looks like this:

{
  "scsRequestId": null,
  "includeMetadata": true,
  "includeHoldings": true,
  "country": [],
  "region": [],
  "oclcSymbol": []
}

Here is the error I am getting:

jq: error: syntax error, unexpected QQSTRING_START, expecting $end (Unix shell quoting issues?) at <top-level>, line 2:
"KZC"
jq: 1 compile error

I want the list of country codes to go into the country array.

Answer 1

-f's argument is the file to read the filter to run from. If you want to read data from a file, that's a use for --slurpfile, not -f.

Thus:

jq --slurpfile countries test_id.txt '.country=$countries' <myfile.json >newfile.json

---

When run with your provided inputs, the resulting contents in newfile.json are:

{
  "scsRequestId": null,
  "includeMetadata": true,
  "includeHoldings": true,
  "country": [
    "NSC",
    "KZC",
    "KCC",
    "KZL",
    "NZG",
    "VRU",
    "ESM",
    "KZF",
    "SFU",
    "EWF",
    "KQY",
    "KQV"
  ],
  "region": [],
  "oclcSymbol": []
}