txt2cdefine: Encode multiline text files into C/C++ #define directives

txt2cdefine

#!/usr/bin/env node

/**
 * txt2cdefine: Encode multiline text files into C/C++ #define directives
 * https://gist.github.com/justindarc/efee6d3d09341618da5af6a58dfd7b69
 *
 * Node.js-based command-line utility for encoding HTML, JS, CSS and other
 * text files into C/C++ #define directives. Useful for embedded hardware
 * applications such as Arduino or ESP8266 where no file system is available
 * for reading external files. The resulting output can saved as a ".h"
 * header file and included in a C/C++ source file.
 *
 *   Usage: txt2cdefine <input_file> <output_file> [macro_name]
 * 
 * input_file:  Relative or absolute path to the text file to be encoded
 *              (e.g. "./index.html")
 * output_file: Relative or absolute path to the C/C++ header file to be
 *              written (e.g. "./index_html.h")
 * macro_name:  Name of the C/C++ macro to be generated in the C/C++ header
 *              file. If omitted, this name will be inferred from the
 *              `output_file` name (e.g. "index_html.h" -> INDEX_HTML())
 */

var HANDLEBARS_REGEXP = /{{\s*(.+)\s*}}/g;

var inputFile  = process.argv[2];
var outputFile = process.argv[3];
var macroName  = process.argv[4];

if (!inputFile || !outputFile) {
  console.log('Usage: txt2cdefine <input_file> <output_file> [macro_name]\n');
  return;
}

var fs = require('fs');
var path = require('path');

macroName = (macroName || path.basename(outputFile, path.extname(outputFile))).toUpperCase();

fs.readFile(inputFile, 'utf8', function(error, inputText) {
  if (error) {
    console.log('ERROR: Invalid input file\n');
    return;
  }

  var args = getUniqueMatches(inputText, HANDLEBARS_REGEXP);

  var inputLines  = inputText.replace(/\r/g, '').replace(/\"/g, '\\"').split('\n');
  var outputLines = [ '#define ' + macroName + '(' + args.join(',') + ') ""\\' ];

  var inputLineCount = inputLines.length;
  inputLines.forEach(function(inputLine, index) {
    inputLine = inputLine.replace(HANDLEBARS_REGEXP, function(match, arg) {
      return '" + ' + arg + ' + "';
    });
    outputLines.push('"' + inputLine + (index < inputLineCount - 1 ? '\\n"\\' : '"'));
  });

  var outputText = outputLines.join('\n');

  fs.writeFile(outputFile, outputText, function(error) {
    if (error) {
      throw error;
    }
  });
});

function getUniqueMatches(string, regexp, index = 1) {
  var matches = [];

  var match;
  while (match = regexp.exec(string)) {
    if (matches.indexOf(match[index]) === -1) {
      matches.push(match[index]);
    }
  }

  return matches;
}