generate.js

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

const rootDataDir = "webpage";
const outputFile = "./output_includes/web_data.h";
const headerFileLocation = "./template_web_data.h.txt";

let files = walkSync(rootDataDir);
let currentFileName = "";
let currentFileLength = -1;
let encoding = "";

let outputString = "";

let headerFile = fs.readFileSync(headerFileLocation, 'utf8');

String.prototype.replaceAll = function(search, replacement) {
    let target = this;
    return target.replace(new RegExp(search, 'g'), replacement);
};

for (let i = 0; i < files.length; i++) {
    currentFileName = files[i];
    encoding = getEncoding(currentFileName);
    outputString += "\n\n\n" + currentFileName + "\nEncoding: " + encoding + " Length:  ";
    let currentData = gotData(fs.readFileSync(rootDataDir + "/" + currentFileName, encoding));

    headerFile = headerFile.replaceAll("##" + currentFileName + "-data##", currentData);
    headerFile = headerFile.replaceAll("##" + currentFileName + "-length##", currentFileLength);
    headerFile = headerFile.replaceAll("##" + currentFileName + "-length-digits##", ("" + currentFileLength).length);
    headerFile = headerFile.replaceAll("##" + currentFileName + "-length_as_array##", formatToArray(currentFileLength));
}

console.log(outputString);

let file = fs.openSync(outputFile, 'w');
fs.writeFile(outputFile, headerFile, function(err) {
    if (err) {
        return console.error(err);
    }

    console.log("The file was saved!");
});

function getEncoding(filename) {
    if (currentFileName.indexOf(".") < 0) {
        return 'hex';
    }
    // eg: filename.tar.gz => gz
    let extension = path.extname(filename).toLowerCase();
    switch (extension) {
        case ".html":
        case ".htm":
        case ".txt":
        case ".css":
        case ".js":
            return 'utf8';
        default:
            return 'hex';
    }

}

function gotData(data) {
    currentFileLength = data.length;
    outputString += currentFileLength + "\n\n\n";
    if (encoding == 'utf8') {
        outputString += '"' + excape(data) + '";';
        return excape(data);
    } else {
        outputString += "{\n" + outputHexArray(data) + "\n};";
        return outputHexArray(data);
    }
}

// source https://gist.github.com/kethinov
// List all files in a directory in Node.js recursively in a synchronous fashion
function walkSync(dir, filelist, path) {
    path = path || "";
    let files = fs.readdirSync(dir);
    filelist = filelist || [];
    files.forEach(function(file) {
        if (fs.statSync(dir + '/' + file).isDirectory()) {
            filelist = walkSync(dir + '/' + file, filelist, path + file + "/");
        } else {
            filelist.push(path + file);
        }
    });
    return filelist;
}

function formatToArray(string) {
    let output = "'";
    let seperator = "', '";
    string = "" + string;
    for (let a = 0; a < string.length - 1; a++) {
        output += string.charAt(a) + seperator;
    }
    return output + string.charAt(string.length - 1) + "',";
}

// source https://github.com/joliss/js-string-escape
function excape(string) {
    return ('' + string).replace(/["'\\\t\n\r\u2028\u2029]/g, function(character) {
        // Escape all characters not included in SingleStringCharacters and
        // DoubleStringCharacters on
        // http://www.ecma-international.org/ecma-262/5.1/#sec-7.8.4
        switch (character) {
            case '"':
            case "'":
            case '\\':
                return '\\' + character;
                // Four possible LineTerminator characters need to be escaped:
            case '\n':
                return '\\n';
            case '\t':
                return '\\t';
            case '\r':
                return '\\r';
            case '\u2028':
                return '\\u2028';
            case '\u2029':
                return '\\u2029';
        }
    });
}
function outputHexArray(string) {
    let returnString = "";
    for (let a = 0; a < string.length; a += 2) {
        returnString += "0x" + string.substring(a, a + 2);

        if (a + 2 !== string.length) {
            returnString += ", ";
        }
        if ((((a - 22) % 24) === 0) && (a !== 0) && (a + 2 !== string.length)) {
            returnString += "\n";
        }
    }
    return returnString;
}