json_extract, json_value, and json_create utilize JavaScript for Automation (JXA) (via osascript -l JavaScript) to parse JSON, so no external dependencies are required and are all fully compatible with all sh, bash, and zsh scripts. They can all be integrated into your own scripts by simply copy-and-pasting the functions into your code, or the script files can executed directly on the command line. json_extract, json_value, and json_create are tested to be compatible with macOS 10.13 High Sierra and newer (but the -f option in json_extract is only available on macOS 10.14 Mojave and newer).
json_extract is designed to make it easy to do pretty advanced (or quite simple) extractions from JSON structures in a very shell-friendly way. No JavaScript notation or special JSON querying knowledge or syntax is needed. All values can be retrieved using simple command line options with no complicated syntax or special characters.
Each capability of json_extract is provided through simple command line options to be able to do things like get all keys of a dictionary using -k or all values using -v as well as the count/length of a dictionary or array using -c. More advanced abilities are also very easy with options for sorting arrays (-s), getting unique elements of arrays (-u), outputting array contents as lines (-l) or NUL (-0) separated values, as well as even more interesting advanced capabilities that you can read about and see examples of in the help/usage information in json_extract.sh.
If you want to integrate the json_extract function into your own scripts, all this powerful functionality only takes up 15 lines! (When the help information is not included.)
json_value is designed just to do direct/simple value retrievals from JSON structures in a very shell-friendly way. No JavaScript notation or special JSON querying knowledge or syntax is needed. All values can be retrieved without even needing any command line options, you simply pass the path of keys/indexes that you want to retrieve as individual arguments.
While json_value is made to be extremely simple and minimal (without many of the advanced capabilities of json_extract), it can still accept both JSON strings or files from stdin or as the first or last argument. There are also 2 extra convenience features for arrays, the first is that values can be retrieve from the end of the array using negative indexes and the next is that the count of an array can be retrieved by passing = as an argument instead of an index number.
If you want to integrate the json_value function into your own scripts, it only takes up 10 lines! Also, there are 5 other variants provided which go down to as few as 3 lines with progressively less and less functionality (such as without reading stdin, without reading files, and without the extra array convenience features) if you want a smaller function with only the functionality you need in your script. For more information and examples, see the help/usage information in json_value.sh. (Some of the techniques used within json_value were originally inspired by Paul Galow and Nathan Henrie.)
json_create is designed to be able to create JSON array and dictionary structures very simply without needing to worry about JSON syntax or escaping special characters. The arguments you specify will be set to the elements of an array, or when the first argument is -d they will be set to the keys and values of a dictionary.
Complex nested/multidimensional data structures can be created using multiple json_create commands by using command substitution to set the output of one json_create command as an argument for another to set that JSON structure as an array element or dictionary value. Also, an existing JSON array or dictionary can be passed to json_create via stdin and it will be used as the starting point so the arguments specified will be added to the input array or dictionary.
If you want to integrate the json_create function into your own scripts, it only takes up 9 lines! For more information and examples, see the help/usage information in json_create.sh.
The formatted JXA source code for json_extract, json_value, and json_create without their shell function wrappers are available at json_extract.jxa, json_value.jxa, and json_create.jxa. These files could be run directly, but are primarily provided as a reference to read the code with the whitespace formatting retained and are not recommened to run directly since the json_extract.sh and json_value.sh shell function wrappers have extra error handling code.