[natnat]

One really cool tool that web programmers should know if they work with JSON data a lot is jq: http://stedolan.github.io/jq/. It's a line-oriented tool like sed, awk, and grep, but it's for manipulating JSON data. It can be really useful for quickly making sense of JSON-formatted log files. For example, you can do something like

    jq -c .'select(.server_name == "slow_server") | .end_time - .start_time' < my_log_file

where your log file might look like

    '{"server": "slow_server", "timings": {"end_time": 1406611619.90, "start_time": 1406611619.10}}'

to get your web request timings.

Because it's line-oriented, it also works seamlessly with other tools, so you can pipe the output to, say, sort, to find the slowest requests.

[troels]

Somewhat similar to xmlstarlet (http://xmlstar.sourceforge.net/docs.php) for xml documents.