Windows Batch - Pretty Print JSON per Script

Question

I have multiple JSON-files on a server, which can only run batch-scripts or command-line tools. The JSON files all aren't formatted properly, meaning there are no tab-spaces at the beginning of lines.

Is there a way, to write a batch-script or run a command-line tool to format the files, so they are normal again?

Answer 1

You will definitely need an external tool for that. I'm using the command-line JSON processor jq - just pass it the Identity filter . and it will pretty print the JSON it's been given as input.

Update: Corrected syntax (where did that come from?), Sorry @Delfic and @Sonata. Even though the empty filter "" from my original answer works, I changed the filter like @Wolf said, as it is indeed mentioned in the manual as the "absolute simplest filter".

Example:

ECHO { "att1": 1, "att2": 2 } | jq .

Output:

{
  "att1": 1,
  "att2": 2
}

If you want to process JSON input directly from the shell, you can also use null input -n:

jq -n "{ "att1" : 1, "att2" : 2 }"

To process a file, do:

jq . dirty.json

...or, if you're so inclined:

TYPE dirty.json | jq .

Answer 2

Super quick way to do it if you have python installed is by typing following in the command prompt or powershell:

type dirty.json | python -m json.tool > pretty.json

where dirty.json is minified or unreadable json and pretty.json is pretty one. you can even put it in a batch file to run it by passing an argument. Its very fast in processing.

Explanation: type is writing the file content to the console but its piped so it is being sent to python's module json.tool and then '>' writes the output into a file called 'pretty.json'. Try without the > pretty.json to see the output in the console.

Answer 3

Windows' cmd capabilities are very limited and support for JSON certainly isn't one of them, so I would advice against creating a batch-script! I would highly recommend the command-line tool xidel though. It prettifies by default.

Stdin:

ECHO {"a":1,"b":2,"c":3} | xidel -se "$json"
{
  "a": 1,
  "b": 2,
  "c": 3
}

(If the input is JSON, xidel will parse and assign it to the (internal) global variable $json)

File/url:

xidel -s "input.json" -e "$json"
#or
xidel -s "https://[...]" -e "$json"
#or
xidel -se "json-doc('file-or-url')"

Write to file:

xidel -s "input.json" -e "$json" > output.json
#or
xidel -s "input.json" -e "file:write('output.json',$json,{'method':'json','indent':true()})"
#or
xidel -se "file:write('output.json',json-doc('input.json'),{'method':'json','indent':true()})"

Process multiple files:

FOR %A IN (*.json) DO @xidel -s %A -e "$json" > %~nA_pretty.json

While this would work for lots of JSON-files in a directory, it's also extremely slow, because xidel is called for each and every JSON-file.
xidel can do this much more efficiently with the integrated EXPath File Module.

xidel -se "file:list(.,false,'json')"

This returns a bare list of all JSON-files in the current directory.
(Equivalent of DIR *.json /B and FOR %A IN (*.json) DO @ECHO %A)

xidel -se "file:list(.,false,'json') ! file:read-text(.)"
#or
xidel -se "for $x in file:list(.,false,'json') return file:read-text($x)"

Both commands return the content of each JSON-file in the current directory.
(Equivalent of FOR %A IN (*.json) DO @TYPE %A)

xidel -se "file:list(.,false,'json') ! json-doc(.)"
#or
xidel -se "for $x in file:list(.,false,'json') return json-doc($x)"

Both commands return the prettified parsed JSON content of each JSON-file in the current directory.
(Equivalent of FOR %A IN (*.json) DO @xidel -s %A -e "$json", but much faster!)

xidel -se "file:list(.,false,'json') ! file:write(substring-before(.,'.json')||'_pretty.json',json-doc(.),{'method':'json','indent':true()})"
#or
xidel -se "for $x in file:list(.,false,'json') return file:write(substring-before($x,'.json')||'_pretty.json',json-doc($x),{'method':'json','indent':true()})"

Both commands write the prettified parsed JSON content of each JSON-file in the current directory to a new file with a filename which ends with "_pretty".

The final command prettified (with the necessary escape-characters):

xidel -se ^"^
  for $x in file:list(.,false,'json') return^
  file:write(^
    substring-before($x,'.json')^|^|'_pretty.json',^
    json-doc($x),^
    {'method':'json','indent':true()}^
  )^
"

Please download a xidel binary from the recommended "Development"-branch to use these queries (and json-doc() in particular).
If you insist on using xidel 0.9.8, then use json(file:read-text($x)) instead of json-doc($x).