Unix command-line JSON parser?

I have created a module specifically designed for command-line JSON manipulation:

https://github.com/ddopson/underscore-cli

• FLEXIBLE - THE "swiss-army-knife" tool for processing JSON data - can be used as a simple pretty-printer, or as a full-powered Javascript command-line
• POWERFUL - Exposes the full power and functionality of underscore.js (plus underscore.string)
• SIMPLE - Makes it simple to write JS one-liners similar to using "perl -pe"
• CHAINED - Multiple command invokations can be chained together to create a data processing pipeline
• MULTI-FORMAT - Rich support for input / output formats - pretty-printing, strict JSON, etc [coming soon]
• DOCUMENTED - Excellent command-line documentation with multiple examples for every command

It allows you to do powerful things really easily:

cat earthporn.json | underscore select '.data .title'
# [ 'Fjaðrárgljúfur canyon, Iceland [OC] [683x1024]',
#   'New town, Edinburgh, Scotland [4320 x 3240]',
#   'Sunrise in Bryce Canyon, UT [1120x700] [OC]',
# ...
#   'Kariega Game Reserve, South Africa [3584x2688]',
#   'Valle de la Luna, Chile [OS] [1024x683]',
#   'Frosted trees after a snowstorm in Laax, Switzerland [OC] [1072x712]' ]

cat earthporn.json | underscore select '.data .title' | underscore count
# 25

underscore map --data '[1, 2, 3, 4]' 'value+1'
# prints: [ 2, 3, 4, 5 ]

underscore map --data '{"a": [1, 4], "b": [2, 8]}' '_.max(value)'
# [ 4, 8 ]

echo '{"foo":1, "bar":2}' | underscore map -q 'console.log("key = ", key)'
# key = foo
# key = bar

underscore pluck --data "[{name : 'moe', age : 40}, {name : 'larry', age : 50}, {name : 'curly', age : 60}]" name
# [ 'moe', 'larry', 'curly' ]

underscore keys --data '{name : "larry", age : 50}'
# [ 'name', 'age' ]

underscore reduce --data '[1, 2, 3, 4]' 'total+value'
# 10

And it has one of the best "smart-whitespace" JSON formatters available:

If you have any feature requests, comment on this post or add an issue in github. I'd be glad to prioritize features that are needed by members of the community.

I prefer python -m json.tool which seems to be available per default on most *nix operating systems per default.

$ echo '{"foo":1, "bar":2}' | python -m json.tool
{
    "bar": 2, 
    "foo": 1
}

Note: Depending on your version of python, all keys might get sorted alphabetically, which can or can not be a good thing. With python 2 it was the default to sort the keys, while in python 3.5+ they are no longer sorted automatically, but you have the option to sort by key explicitly:

$ echo '{"foo":1, "bar":2}' | python3 -m json.tool --sort-keys
{
    "bar": 2, 
    "foo": 1
}

You can use this command-line parser (which you could put into a bash alias if you like), using modules built into the Perl core:

perl -MData::Dumper -MJSON::PP=from_json -ne'print Dumper(from_json($_))'

If you're looking for a portable C compiled tool:

https://stedolan.github.io/jq/

From the website:

jq is like sed for JSON data - you can use it to slice and filter and map and transform structured data with the same ease that sed, awk, grep and friends let you play with text.

jq can mangle the data format that you have into the one that you want with very little effort, and the program to do so is often shorter and simpler than you’d expect.

Tutorial: https://stedolan.github.io/jq/tutorial/
Manual: https://stedolan.github.io/jq/manual/
Download: https://stedolan.github.io/jq/download/