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\":         


        

Answer 1

I use the "space" argument of JSON.stringify to pretty-print JSON in JavaScript.

Examples:

// Indent with 4 spaces
JSON.stringify({"foo":"lorem","bar":"ipsum"}, null, 4);

// Indent with tabs
JSON.stringify({"foo":"lorem","bar":"ipsum"}, null, '\t');

From the Unix command-line with Node.js, specifying JSON on the command line:

$ node -e "console.log(JSON.stringify(JSON.parse(process.argv[1]), null, '\t'));" \
  '{"foo":"lorem","bar":"ipsum"}'

Returns:

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

From the Unix command-line with Node.js, specifying a filename that contains JSON, and using an indent of four spaces:

$ node -e "console.log(JSON.stringify(JSON.parse(require('fs') \
      .readFileSync(process.argv[1])), null, 4));"  filename.json

Using a pipe:

echo '{"foo": "lorem", "bar": "ipsum"}' | node -e \
"\
 s=process.openStdin();\
 d=[];\
 s.on('data',function(c){\
   d.push(c);\
 });\
 s.on('end',function(){\
   console.log(JSON.stringify(JSON.parse(d.join('')),null,2));\
 });\
"