jsonpps

A streaming JSON pretty printer that can format multi-GB input files. This repo is being archived and made read-only on August 30th, 2021 because it is dormant.

Pretty prints a whitespace-separated sequence of JSON values. Example:

$ echo 'false 0 "string" [1,2,3] {"a":4} null' | jsonpps
false
0
"string"
[ 1, 2, 3 ]
{
  "a" : 4
}
null

Why yet another JSON pretty printer?

• Processes very large JSON files in a memory-efficient way. Does not read entire files into memory at once.

• Preserves the order of key/value pairs in JSON objects unlike, for example, python -mjson.tool.

• Accepts input that already has some formatting such as newline characters.

• Unless --strict is specified, accepts certain JavaScript syntax such as comments, unquoted keys, single quoted strings. Example:

  $ echo "{key: 'value' /*inline comment*/} // line comment" | jsonpps
  {
    "key" : "value"
  }
  

Uses the [Jackson streaming JSON parser] (http://wiki.fasterxml.com/JacksonHome).

Usage

$ jsonpps -h
usage:
    jsonpps              - pretty print stdin
    jsonpps -            - pretty print stdin
    jsonpps <file> ...   - pretty print file(s)

options:
    -o <file>            - output file
    --strict             - reject non-conforming json

Installation

Requires Java and Maven.

# Download and build streaming jsonpps
git clone git@github.com:bazaarvoice/jsonpps.git
cd jsonpps
mvn clean package

# Install
sudo ln -s $(pwd)/jsonpps /usr/local/bin/

Or, if you have [Homebrew on OS/X] (http://brew.sh/):

brew install https://raw.github.com/shawnsmith/homebrew/master/Library/Formula/jsonpps.rb