query_json_stdin v1.0.59

This package is experimental

Do not install using npm install, just run using npx. Wrapper for jsonpath package for use in command line using pipes.

• reads stdin (standard input) for JSON string
• converts string to JSON object
• runs jsonpath on the string
• returns the first match.
• to avoid trouble, does not open a filesystem file.

Typically called from a script to determine version and name of package.json.

Example usage on a package.json file (git-bash on windows):

# get version tag:  
cat package.json | npx query_json_stdin --queryStr='$..version'
# get name tag (without quotes)  
cat package.json | npx query_json_stdin --queryStr='$..name'
# returns fragment of JSON. Since query returns an object, stringify() gets applied to make tags have quotes:
cat package.json | npx query_json_stdin --queryStr='$..dependencies'
# optional position argument for multi-matches. Defaults to first match:  
cat package.json | npx query_json_stdin [--position=2 --position=all] --queryStr='$..name'

• Also see file2.json for more examples.
• For developing, all source code is file queryJSONstdin.js. See comments in file about how to run js file locally.
  Problem: I attempted to make a visual studio launch.json file for debugging but could not figure out how to pipe input to the run command.
  Problem: tried to add a link to the file like in github markdown, but it won't work

About npx and how it knows what to do:

• When "npx query_json_stdin" is run on a terminal window, npmjs gets searched for the package query_json_stdin.
  Inside this package, file package.json is read to get this line:
  "bin": "queryJSONstdin.js",
  This tells npx to run file queryJSONstdin.js on your terminal. This file can also invoke a bundle.js and be the entry for a really big application.
• The section:

  "dependencies": {
      "jsonpath": "^1.1.1",
      "yargs": "^17.7.2"
  },

  is also examined and packages downloaded before running if needed.
• The downloaded npm packages go into the global location. On windows it's C:\Users\zzz\AppData\Local\npm-cache_npx\xxxx\node_modules