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    <p>To quickly extract the values for a particular key, I personally like to use "grep -o", which only returns the regex's match. For example, to get the "text" field from tweets, something like:</p> <pre><code>grep -Po '"text":.*?[^\\]",' tweets.json </code></pre> <p>This regex is more robust than you might think; for example, it deals fine with strings having embedded commas and escaped quotes inside them. I think with a little more work you could make one that is actually guaranteed to extract the value, if it's atomic. (If it has nesting, then a regex can't do it of course.)</p> <p>And to further clean (albeit keeping the string's original escaping) you can use something like: <code>| perl -pe 's/"text"://; s/^"//; s/",$//'</code>. (I did this for <a href="https://gist.github.com/1024217" rel="noreferrer">this analysis</a>.)</p> <p>To all the haters who insist you should use a real JSON parser -- yes, that is essential for correctness, but</p> <ol> <li>To do a really quick analysis, like counting values to check on data cleaning bugs or get a general feel for the data, banging out something on the command line is faster. Opening an editor to write a script is distracting.</li> <li><code>grep -o</code> is orders of magnitude faster than the Python standard <code>json</code> library, at least when doing this for tweets (which are ~2 KB each). I'm not sure if this is just because <code>json</code> is slow (I should compare to yajl sometime); but in principle, a regex should be faster since it's finite state and much more optimizable, instead of a parser that has to support recursion, and in this case, spends lots of CPU building trees for structures you don't care about. (If someone wrote a finite state transducer that did proper (depth-limited) JSON parsing, that would be fantastic! In the meantime we have "grep -o".)</li> </ol> <p>To write maintainable code, I always use a real parsing library. I haven't tried <a href="https://github.com/micha/jsawk" rel="noreferrer">jsawk</a>, but if it works well, that would address point #1.</p> <p>One last, wackier, solution: I wrote a script that uses Python <code>json</code> and extracts the keys you want, into tab-separated columns; then I pipe through a wrapper around <code>awk</code> that allows named access to columns. <a href="https://github.com/brendano/tsvutils" rel="noreferrer">In here: the json2tsv and tsvawk scripts</a>. So for this example it would be:</p> <pre><code>json2tsv id text &lt; tweets.json | tsvawk '{print "tweet " $id " is: " $text}' </code></pre> <p>This approach doesn't address #2, is more inefficient than a single Python script, and it's a little brittle: it forces normalization of newlines and tabs in string values, to play nice with awk's field/record-delimited view of the world. But it does let you stay on the command line, with more correctness than <code>grep -o</code>.</p>
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    1. POParsing JSON with Unix tools
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    1. USBrendan OConnor
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    1. COwhat if parameter last in tuple thwn at the end no comma but right brace. And +1 for sure.
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    2. COHi Yola, right, it depends on the input. You have to look at it first.
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    3. COYou forgot about integer values. `grep -Po '"text":(\d*?,|.*?[^\\]",)'`
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