jeg, a json grep

Jeg was born from the repeated annoyance of trying to quickly glance at some JSON-fomatted data and being unable to really get it, then have to pass it through a javascript formatter and then later go and trying to find the data that I alread know was under the "name" field but was impossible to discern in a 800 character single line string.

Ah, how I craved for the simplicty of tabular data that I could slice and dice with grep and cut.

Thus, Jeg was born.

So what is it, concretely?

Simply put, it allows you to select parts of a json structure using JSONPath. For example, if you want to find a user's real name on twitter from this

{"url":"http://www.riffraff.info","description":"Code Monkey, Professional Student, Geek","time_zone":"Rome","profile_sidebar_fill_color":"e0ff92","status":{"in_reply_to_user_id":null,"in_reply_to_status_id":null,"in_reply_to_screen_name":null,"created_at":"Sun Jan 24 16:16:28 +0000 2010","source":"<a href=\"http://www.tweetdeck.com/\" rel=\"nofollow\">TweetDeck</a>","truncated":false,"id":8153979023,"favorited":false,"text":"darn I have to publish a forked gem, and can't understand the state of the art in how to do so :("},"statuses_count":447,"created_at":"Tue Jan 02 11:27:37 +0000 2007","profile_sidebar_border_color":"87bc44","contributors_enabled":false,"favourites_count":3,"followers_count":142,"profile_image_url":"http://a3.twimg.com/profile_images/88180929/nyussi_normal.jpg","profile_text_color":"000000","lang":"en","geo_enabled":true,"notifications":null,"profile_background_image_url":"http://s.twimg.com/a/1264119427/images/themes/theme1/bg.png","friends_count":171,"protected":false,"screen_name":"riffraff","following":null,"profile_link_color":"0000ff","location":"milan/rome/budapest","name":"gabriele renzi","verified":false,"profile_background_tile":false,"id":446303,"utc_offset":3600,"profile_background_color":"9ae4e8"

you can simply query the api via curl and use jeg to extract the name field:

$ curl  http://twitter.com/users/show.json?screen_name=riffraff -s | jeg name
  gabriele renzi

Or if you want the 'text' fields in a list of objects from the Cascaad APIs

$ curl api.cascaad.com/2/messages/latest.json?type=NEWS -s  | jeg $..text
  counter the Tea Party movement, which is abt stopping things, with Innovation Movement, which is abt starting things.  http://bit.ly/4o35m4
  Bringing Silicon Valley to Sacramento: Why Entrepreneurs Need to Help Rebuild California's IT Systems http://tcrn.ch/8pD3Ki by @vwadhwa
  Spectacular Thomas Friedman OpEd on making 2010 the Year of Innovation and Start-Up America  - http://nyti.ms/4qk8Jh

Just this?

Well, a bit more, see jeg -h

Installation

Jeg depends on the riffraff_jsonpath and json libraries. The former is a small fork of the original jsonpath gem without warnings and with a couple of tiny fixes.

You can just dump the single jeg script in some directory in your path and make it executable to install it, or you can user rubygems

gem install jeg

And that's it.

Running the tests

As of now no unit tests were written but the command line examples are extracted and executed by the code in test/ (if you have a checkout and you are reading this file) just run them with ruby having the script in your path, or use rake test you shall see something like

Loaded suite test/docs
Started
...............
Finished in 9.999814 seconds.

15 tests, 15 assertions, 0 failures, 0 errors

If you don't please report it at [http://github.com/riffraff/jeg/issues](http://github.com/riffraff/jeg/issues)

License

jeg is free software (pretend you wrote it, sell it for huge profit) but see accompanying LICENSE file for the full text of the license.