jsonlint

Introduction

jsonlint is a command-line tool for Mac OS X that can be used to parse, validate, and convert JSON text files.

It makes use of a slightly modified version of Jonathan Wight's TouchJSON for JSON processing: https://github.com/atomicbird/TouchJSON.

Getting jsonlint

Since jsonlint includes TouchJSON as a git submodule, you'll need to clone recursively to get all the necessary code:

git clone --recursive git://github.com/atomicbird/jsonlint.git

License

jsonlint is licensed under the MIT license.

Usage

jsonlint reads from standard input and writes to standard output. Its simplest usage echoes the incoming JSON to stdout if the JSON is valid. If not, it prints hopefully-useful error message to stderr.

% jsonlint < ex5.json
{"menu":{"items":[{"id":"Open"},{"id":"OpenNew","label":"Open New"},null,{"id":"ZoomIn","label":"Zoom In"},{"id":"ZoomOut","label":"Zoom Out"},{"id":"OriginalView","label":"Original View"},null,{"id":"Quality"},{"id":"Pause"},{"id":"Mute"},null,{"id":"Find","label":"Find..."},{"id":"FindAgain","label":"Find Again"},{"id":"Copy"},{"id":"CopyAgain","label":"Copy Again"},{"id":"CopySVG","label":"Copy SVG"},{"id":"ViewSVG","label":"View SVG"},{"id":"ViewSource","label":"View Source"},{"id":"SaveAs","label":"Save As"},null,{"id":"Help"},{"id":"About","label":"About Adobe CVG Viewer..."}],"header":"SVG Viewer"}}

% jsonlint < fail17.json
["Illegal backslash escape: 017"]

Arguments

-q
--quiet

Don't echo the input to the output.

-f
--formatted

Format the output for easier reading by humans.

-p
--plist

Print the output in property list format rather than as JSON.

-a
--force-array

Force the incoming JSON to be treated as an array. If an array is not found, an error is printed and 1 is returned, even if the incoming data is valid non-array JSON.

-d
--force-dict

Force the incoming JSON to be treated as dictionary. If a dictionary is not found, an error is printed and 1 is returned, even if the incoming data is valid non-dictionary JSON.

-e
--encoding-search

Run through possible string encodings in the hope of finding one that matches incoming data. Useful if you're dealing with a server API that includes, for example, ISO-Latin-1 or MacOSRoman in JSON. This may result in successfully parsing JSON that violates RFC 4627 (http://www.ietf.org/rfc/rfc4627.txt), but sometimes such abominations are necessary.

Return codes

Returns 0 if the incoming JSON is valid, 1 if it is not.

Examples

Formatted output

jsonlint --format < ex1.json
{
  "glossary" : {
	  "title" : "example glossary",
	  "GlossDiv" : {
		  "title" : "S",
		  "GlossList" : {
			  "GlossEntry" : {
				  "Abbrev" : "ISO 8879:1986",
				  "SortAs" : "SGML",
				  "GlossTerm" : "Standard Generalized Markup Language",
				  "GlossDef" : {
					  "GlossSeeAlso" : [
						  "GML",
						  "XML"
						  ],
					  "para" : "A meta-markup language, used to create markup languages such as DocBook."
					  },
				  "GlossSee" : "markup",
				  "ID" : "SGML",
				  "Acronym" : "SGML"
				  }
			  }
		  }
	  }
  }

Property list output

jsonlint --format --plist < ex1.json
{
	glossary =     {
		GlossDiv =         {
			GlossList =             {
				GlossEntry =                 {
					Abbrev = "ISO 8879:1986";
					Acronym = SGML;
					GlossDef =                     {
						GlossSeeAlso =                         (
							GML,
							XML
						);
						para = "A meta-markup language, used to create markup languages such as DocBook.";
					};
					GlossSee = markup;
					GlossTerm = "Standard Generalized Markup Language";
					ID = SGML;
					SortAs = SGML;
				};
			};
			title = S;
		};
		title = "example glossary";
	};
}

Using jsonlint with other tools

Any command-line tool that writes to standard output can be trivially used with jsonlint, for example:

curl http://search.twitter.com/search.json?q=foo | jsonlint -p