A command-line tool for manipulating JSON using JSONPath.
Applying a JSONPath query on a file
% jsonpath '$.store.book[*].author' sample.json -p
[
"Nigel Rees",
"Evelyn Waugh",
"Herman Melville",
"J. R. R. Tolkien"
]Viewing path to matching results
% jsonpath '$.store.book[*].author' sample.json -lp
[
"$['store']['book'][0]['author']",
"$['store']['book'][1]['author']",
"$['store']['book'][2]['author']",
"$['store']['book'][3]['author']"
]Getting help with arguments and options
% jsonpath help simple
OVERVIEW: Simplified interface to quickly run a JSONPath query against a file
USAGE: jsonpath simple <query><input> [-l] [-p]
ARGUMENTS:
<query> JSONPath query
<input> input file
OPTIONS:
-l Output the path to the results instead of the results
themselves
-p Pretty print the result JSON
-h, --help Show help information.mint install KittyMac/jsonpath
The original Stefan Goessner JsonPath implemenentation was released in 2007, and from it spawned dozens of different implementations. This JSONPath Comparison chart shows the wide array of available implemenations, and at the time of this writing a Swift implementation is not present (note that there exists the SwiftPath project, but it is not included in said chart due to critical errors when running on Linux.
The rest of this section is largely adapted from the Jayway JsonPath Getting Started section.
| Operator | Description |
|---|---|
$ | The root element to query. This starts all path expressions. |
@ | The current node being processed by a filter predicate. |
* | Wildcard. Available anywhere a name or numeric are required. |
.. | Deep scan. Available anywhere a name is required. |
.<name> | Dot-notated child |
['<name>' (, '<name>')] | Bracket-notated child or children |
[<number> (, <number>)] | Array index or indexes |
[start:end] | Array slice operator |
[?(<expression>)] | Filter expression. Expression must evaluate to a boolean value. |
Functions can be invoked at the tail end of a path - the input to a function is the output of the path expression. The function output is dictated by the function itself.
| Function | Description | Output type | |
|---|---|---|---|
| min() | Provides the min value of an array of numbers | Double | |
| max() | Provides the max value of an array of numbers | Double | |
| avg() | Provides the average value of an array of numbers | Double | |
| stddev() | Provides the standard deviation value of an array of numbers | Double | |
| length() | Provides the length of an array | Integer | |
| sum() | Provides the sum value of an array of numbers | Double | |
| keys() | Provides the property keys (An alternative for terminal tilde ~) | Set<E> | |
| concat(X) | Provides a concatinated version of the path output with a new item | like input | |
| append(X) | add an item to the json path output array | like input |
Filters are logical expressions used to filter arrays. A typical filter would be [?(@.age > 18)] where @ represents the current item being processed. More complex filters can be created with logical operators && and ||. String literals must be enclosed by single or double quotes ([?(@.color == 'blue')] or [?(@.color == "blue")]).
| Operator | Description |
|---|---|
| == | left is equal to right (note that 1 is not equal to '1') |
| != | left is not equal to right |
| < | left is less than right |
| <= | left is less or equal to right |
| > | left is greater than right |
| >= | left is greater than or equal to right |
| =~ | left matches regular expression [?(@.name =~ /foo.*?/i)] |
| in | left exists in right [?(@.size in ['S', 'M'])] |
| nin | left does not exists in right |
| subsetof | left is a subset of right [?(@.sizes subsetof ['S', 'M', 'L'])] |
| anyof | left has an intersection with right [?(@.sizes anyof ['M', 'L'])] |
| noneof | left has no intersection with right [?(@.sizes noneof ['M', 'L'])] |
| size | size of left (array or string) should match right |
| empty | left (array or string) should be empty |
Given the json
{"store": {"book": [{"category": "reference","author": "Nigel Rees","title": "Sayings of the Century","display-price": 8.95,"bargain": true},{"category": "fiction","author": "Evelyn Waugh","title": "Sword of Honour","display-price": 12.99,"bargain": false},{"category": "fiction","author": "Herman Melville","title": "Moby Dick","isbn": "0-553-21311-3","display-price": 8.99,"bargain": true},{"category": "fiction","author": "J. R. R. Tolkien","title": "The Lord of the Rings","isbn": "0-395-19395-8","display-price": 22.99,"bargain": false}],"bicycle": {"color": "red","display-price": 19.95,"foo:bar": "fooBar","dot.notation": "new","dash-notation": "dashes"}}}| JsonPath (click link to try) | Result |
|---|---|
| $.store.book[*].author | The authors of all books |
| $..['author','title'] | All authors and titles |
| $.store.* | All things, both books and bicycles |
| $.store..display-price | The price of everything |
| $..book[2] | The third book |
| $..book[-2] | The second to last book |
| $..book[0,1] | The first two books |
| $..book[:2] | All books from index 0 (inclusive) until index 2 (exclusive) |
| $..book[1:2] | All books from index 1 (inclusive) until index 2 (exclusive) |
| $..book[-2:] | Last two books |
| $..book[2:] | Book number two from tail |
| $..book[?(@.isbn)] | All books with an ISBN number |
| $.store.book[?(@.display-price < 10)] | All books in store cheaper than 10 |
| $..book[?(@.bargain == true)] | All bargain books in store |
| $..book[?(@.author =~ /.*REES/i)] | All books matching regex (ignore case) |
| $..* | Give me every thing |
| $..book.length() | The number of books |