feat(component): Adds a cli interface to the utility via json2md

Adds cli.js aliased when install in the package.json to json2md in the bin field, takes an input
json file, stdin json and outputs to stdout or specified 'md' file.

Author: Chris Paterson

README.md

@@ -12,6 +12,8 @@ are also very welcome.
 
 Install the normal way: `npm install json-schema-to-markdown`
 
+or if using cli, install globally: `npm install -g json-schema-to-markdwon`
+
 Use it like this:
 
 ```js
@@ -20,6 +22,22 @@ var schema = // An object that is a valid JSON Schema
 var markdown = parse(schema)
 ```
 
+### CLI
+
+`json2md /path/to/schema_file.json`
+
+**NOTE: input file must end with .json**
+
+or
+
+`cat /path/to/schema_file.json | json2md`
+
+default output is to stdout but you may specify an output file
+
+`json2md /path/to/schema_file.json /path/to/output.md`
+
+**NOTE: output file must end with .md**
+
 There are plenty of examples in the [test folder](./test), but a very
 simple example would be as follows:
 

cli.js

@@ -0,0 +1,61 @@
+#!/usr/bin/env node
+
+var parse = require('./index')
+var fs = require("fs");
+var args = process.argv.slice(2);
+var inputFile;
+var outputFile;
+
+var out = function(output) {
+
+  output = parse(JSON.parse(output));
+
+  if(outputFile) {
+
+    fs.writeFileSync(outputFile, output);
+    console.log("created " + outputFile);
+
+  } else {
+
+    console.log(output);
+
+  }
+};
+
+for(var i =0; i < args.length; i++) {
+  if(~args[i].indexOf('.json')) {
+    inputFile = args[i];
+  } else if(~args[i].indexOf('.md')) {
+    outputFile = args[i];
+  }
+}
+
+if(inputFile) {
+
+  if (fs.existsSync(inputFile)) {
+
+    out(fs.readFileSync(inputFile, 'utf8'));
+
+  } else {
+
+    throw new Error("File does not exist: " + inputFile);
+
+  }
+
+} else if (process.stdin) {
+
+  var schema = '';
+  process.stdin.setEncoding('utf8');
+  process.stdin.on('readable', () => {
+    let chunk;
+    // Use a loop to make sure we read all available data.
+    while ((chunk = process.stdin.read()) !== null) {
+      schema += chunk;
+    }
+  });
+
+  process.stdin.on('end', () => {
+    out(schema);
+  });
+
+}

package.json

@@ -3,6 +3,9 @@
   "version": "1.1.1",
   "description": "Turn a JSON Schema into a markdown file.",
   "main": "index.js",
+  "bin": {
+    "json2md": "./cli.js"
+  },
   "scripts": {
     "commit": "git-cz",
     "test": "tape test/*.js"