How to convert a huge single line json file to a multi line file without opening it?

Question

I have a large (around 200Mb) single-line json file and I want to convert this to a more readable multi-line json (or txt) file.

I tried to open the file with text editors like sublime text and it takes forever to open. So, I would like to make the conversion without opening the file.

Therefore, I cannot use the interface suggested in this SO question.

I tried to pretty-print the json file as suggested in this answer by doing the following.

cat myjsonfile.json | python -m json.tool > pretty.json

But the terminal prints the following message and I get an empty pretty.json file.

Extra data: line 1 column 34255 - line 1 column 173769197 (char 34254 - 173769196)

I'm thinking of installing visual basic, just to convert the file. But is there a better and efficient way to do the conversion?

Answer 1

The simplest method would be using jq to pretty print the json:

jq . myjsonfile.json > pretty.json

But from the python output, I suspect the json file may be ill-formed.

Answer 2

alternatively, you can use jtc unix utility to pretty-print your one-liner json:

jtc myjsonfile.json

you can use there -t option to control indentation.
If you like to convert myjsonfile.json from one-liner into pretty-printed, then use option -f:

jtc -f myjsonfile.json

btw, to convert it back to one-liner again: jtc -fr myjsonfile.json

PS> Disclosure: I'm the creator of the jtc - shell cli tool for JSON operations