How can I pretty-print JSON in a shell script?

Question

Is there a (Unix) shell script to format JSON in human-readable form?

Basically, I want it to transform the following:

{ "foo": "lorem", "bar": "ipsum" }

... into something like this:

{
    "foo": "lorem",
    "bar": "ipsum"
}

Answer 1

yajl is very nice, in my experience. I use its json_reformat command to pretty-print .json files in vim by putting the following line in my .vimrc:

autocmd FileType json setlocal equalprg=json_reformat

Answer 2

I usually just do:

echo '{"test":1,"test2":2}' | python -mjson.tool

And to retrieve select data (in this case, "test"'s value):

echo '{"test":1,"test2":2}' | python -c 'import sys,json;data=json.loads(sys.stdin.read()); print data["test"]'

If the JSON data is in a file:

python -mjson.tool filename.json

If you want to do it all in one go with curl on the command line using an authentication token:

curl -X GET -H "Authorization: Token wef4fwef54te4t5teerdfgghrtgdg53" http://testsite/api/ | python -mjson.tool

Answer 3

Vanilla Bash

A simple Bash script (grep/awk) for pretty JSON printing, without third party install:

json_pretty.sh

#/bin/bash

grep -Eo '"[^"]*" *(: *([0-9]*|"[^"]*")[^{}\["]*|,)?|[^"\]\[\}\{]*|\{|\},?|\[|\],?|[0-9 ]*,?' | awk '{if ($0 ~ /^[}\]]/ ) offset-=4; printf "%*c%s\n", offset, " ", $0; if ($0 ~ /^[{\[]/) offset+=4}'

---

Examples:

1) Read file and pretty print in console

cat file.json | json_pretty.sh

2) Use with the windows GIT Bash from file to file (UTF8 based):

cat fileIn.json |sh.exe json_pretty.sh > fileOut.json

Answer 4

I use jshon to do exactly what you're describing. Just run:

echo $COMPACTED_JSON_TEXT | jshon

You can also pass arguments to transform the JSON data.

Answer 5

Check out Jazor. It's a simple command line JSON parser written in Ruby.

gem install jazor
jazor --help

Answer 6

I wrote a tool that has one of the best "smart whitespace" formatters available. It produces more readable and less verbose output than most of the other options here.

underscore-cli

This is what "smart whitespace" looks like:

I may be a bit biased, but it's an awesome tool for printing and manipulating JSON data from the command-line. It's super-friendly to use and has extensive command-line help/documentation. It's a Swiss Army knife that I use for 1001 different small tasks that would be surprisingly annoying to do any other way.

Latest use-case: Chrome, Dev console, Network tab, export all as HAR file, "cat site.har | underscore select '.url' --outfmt text | grep mydomain"; now I have a chronologically ordered list of all URL fetches made during the loading of my company's site.

Pretty printing is easy:

underscore -i data.json print

Same thing:

cat data.json | underscore print

Same thing, more explicit:

cat data.json | underscore print --outfmt pretty

This tool is my current passion project, so if you have any feature requests, there is a good chance I'll address them.