前面说了，在控制台执行egret命令其实就是node /Applications/EgretLauncher.app/Contents/Resources/app/engine/mac/selector.js
所以selector.js里面的js代码就是他做的事情。
1 /* 2 3 此文件需要放在引擎安装目录 4 例如 C:Program FilesEgretEgretEnginewinselector.js 5 或 /Applications/EgretEngine.app/Contents/Resources/mac/selector.js 6 7 根据命令行参数 8 --ev 2.4.3 9 或项目中 egretProperties.json 中指定的引擎版本来执行对应的引擎。 10 11 引擎选择优先级为 12 --ev 13 egretProperties.json 14 默认引擎 15 16 17 历史版本的引擎位置为： 18 Mac: /Users/${user}/Library/Application Support/Egret/engine/${version}/ 19 Windows: %AppData%/Egret/engine/${version}/ 20 其中根目录下有 config.json（可选，默认没有） 记录默认引擎和自定义引擎目录 21 { 22 "egret":{ 23 "2.0.5":{ 24 "root":"D:\Work\egret-core\" //自定义目录 25 }, 26 "defaultEngine":"2.4.3" 27 } 28 } 29 30 31 默认版本查找顺序 32 config.json defaultEngine 指定的版本号 33 config.json 中指定的自定义路径 34 引擎安装目录/egret 35 历史版本根目录/${version} 36 EGRET_PATH环境变量仅仅作为兼容以前版本使用 37 38 39 40 egret versions 命令输出可用的引擎版本 41 Egret Engine 2.4.3 D:/Program Files/Egret/EgretEngine/win/egret/ 42 Egret Engine 2.0.5 D:/Work/egret-core/ 43 44 45 */ 46 var FS = require("fs"); 47 var Path = require("path"); 48 var selector = require('../egret').selector; 49 var stat = require('../../stat/egretStat'); 50 var DEFAULT_ENGINE = "defaultEngine"; 51 var args; 52 var osLocal = require("../os-local.js"); 53 var i18n = osLocal(); 54 i18n = i18n.toLowerCase(); 55 if (i18n == "zh_cn" || i18n == "zh_tw" || i18n == "zh_hk") { 56 var language = 'zh'; 57 } else { 58 language = 'en' 59 } 60 61 var engines; 62 var localsMessages = { 63 en: { 64 1: "Can not find Egret Engine {0}, please install it with Egret Launcher.", 65 2: "Can not find Egret Engine, please open Egret Launcher and install.", 66 3: "Egret Engine latest version: {0} Egret Engine current version: {1} You can upgrade your project via egret upgrade", 67 4: "Egret Engine latest version: {0}", 68 5: "Error! The egretProperties.json is not a valid json.", 69 6: "egret upgrade Need to specify version usage: egret upgrade --egretversion [target version] Current upgradeable version:", 70 7: "Error! The egretProperties.json have no egret_version.", 71 8: "The specified version number must be greater than the version number of the current project, current project version {0}", 72 9: "The current project version is already {0}.", 73 10: "current project version", 74 11: "egret make Need to specify version usage: egret make --egretversion [target version]" 75 }, 76 zh: { 77 1: "未找到 Egret Engine {0} ，请在Egret Launcher中安装该版本引擎", 78 2: "尚未安装引擎，请在Egret Launcher中安装该版本引擎", 79 3: "您安装的最新引擎版本为 {0} 当前项目使用版本为 {1} 您可以执行 egret upgrade 命令升级项目", 80 4: "您安装的最新引擎版本为 {0}", 81 5: "错误！！ egretProperties.json 不是有效的 json 文件", 82 6: "egret upgrade 需要指定升级版本 usage: egret upgrade --egretversion [target version] 当前可升级版本号：", 83 7: "错误！！ egretProperties.json 没有有效的 egret_version", 84 8: "指定的版本号必须大于当前项目的版本号，当前项目版本{0}", 85 9: "当前项目版本已是{0}，无需升级", 86 10: "当前项目版本", 87 11: "egret make 需要指定引擎版本 usage: egret make --egretversion [target version]" 88 } 89 }; 90 var commandsToSkip = { 91 "upgrade": true 92 }; 93 function entry() { 94 engines = selector.getAllEngineVersions(); 95 args = parseArgs(); 96 var requestVersion = args.egretversion || args.ev; 97 if (requestVersion === true) 98 requestVersion = undefined; 99 var handled = false; 100 let statArgs = process.argv.concat(); 101 statArgs.splice(0, 2); 102 var statData = { 103 command: args.command, 104 parameters: statArgs.join(' '), 105 path: process.cwd(), 106 source: process.title 107 }; 108 let userName = selector.getUserName(); 109 if (args.command === "versions") { 110 handled = true; 111 printVersions(); 112 } 113 if(args.command === "paths"){ 114 handled = true; 115 printTools(); 116 } 117 if(handled){ 118 stat.egretStat("cmd", userName, statData); 119 return; 120 } 121 var projectVersion = getProjectVersion(); 122 statData["egretversion"] = projectVersion; 123 stat.egretStat("cmd", userName, statData); 124 var projectVersion = getProjectVersion(); 125 var latestVersion = selector.chooseLatestEngine(); 126 if (!latestVersion) { 127 console.log(tr(2)); 128 process.exit(2); 129 return; 130 } 131 if (args.command === "make") { 132 if (!requestVersion) { 133 console.log(tr(11)); 134 return; 135 } 136 } 137 if (args.command == "upgrade") { 138 if (!projectVersion) { 139 console.log(tr(7)); 140 return; 141 } 142 if (!requestVersion) { 143 let upgradeableEngines = []; 144 if (projectVersion) { 145 Object.keys(engines).sort(compareVersion).reverse().forEach(function (v) { 146 let value = compareVersion(engines[v].version, projectVersion); 147 if (value > 0) { 148 upgradeableEngines.push(engines[v].version); 149 } else if (value === 0) { 150 upgradeableEngines.push(engines[v].version + " [" + tr(10) + "]"); 151 } 152 }); 153 } 154 console.log(tr(6)); 155 upgradeableEngines.forEach(function (e) { 156 console.log(e); 157 }); 158 return; 159 } 160 if (compareVersion(requestVersion, projectVersion) < 0) { 161 console.log(tr(8, projectVersion)); 162 return; 163 } 164 if (compareVersion(requestVersion, projectVersion) == 0) { 165 console.log(tr(9, projectVersion)); 166 return; 167 } 168 } 169 if (requestVersion || (projectVersion && !(args.command in commandsToSkip))) { 170 requestVersion = requestVersion || projectVersion; 171 if (!engines[requestVersion]) { 172 console.log(tr(1, requestVersion)); 173 process.exit(1); 174 return; 175 } 176 if (projectVersion && !(args.command in commandsToSkip) && compareVersion(projectVersion, latestVersion.version) < 0) { 177 console.log(tr(3, latestVersion.version, projectVersion)); 178 } 179 executeVersion(requestVersion); 180 return; 181 } 182 if (!handled) { 183 executeVersion(latestVersion.version, latestVersion.root); 184 } 185 } 186 function printVersions() { 187 if (!engines) { 188 getAllEngineVersions(); 189 } 190 Object.keys(engines).sort(compareVersion).reverse().forEach(function (v) { 191 console.log(("Egret Engine " + engines[v].version + " ") + engines[v].root); 192 }); 193 } 194 function printTools() { 195 let tools = selector.getInstalledTools(); 196 console.log(JSON.stringify(tools, null, " ")); 197 } 198 function executeVersion(version, root) { 199 root = root || engines[version].root; 200 var bin = selector.getBin(root); 201 process.env["EGRET_PATH"] = root; 202 //Fix 1.5 can not find typescript lib 203 if (process['mainModule']) { 204 process['mainModule'].filename = bin; 205 } 206 require(bin); 207 return true; 208 } 209 210 function getProjectVersion() { 211 var dir; 212 if (args.command != "create_app") { 213 dir = args.projectDir; 214 } 215 else { 216 dir = args["f"]; 217 } 218 var propsPath = file.joinPath(dir, "egretProperties.json"); 219 if(!file.exists(propsPath)){ 220 propsPath = file.joinPath(dir, "package.json"); 221 } 222 if (file.exists(propsPath)) { 223 var jsonText = file.read(propsPath); 224 var props; 225 try { 226 props = JSON.parse(jsonText); 227 } 228 catch (e) { 229 console.log(tr(5)); 230 process.exit(2); 231 } 232 if (props["compilerVersion"]) { 233 return props["compilerVersion"]; 234 } 235 if (props["egret_version"]) { 236 return props["egret_version"]; 237 } 238 return props["version"]; 239 } 240 return null; 241 } 242 243 function tr(code) { 244 var args = []; 245 for (var _i = 1; _i < arguments.length; _i++) { 246 args[_i - 1] = arguments[_i]; 247 } 248 var messages = localsMessages[language]; 249 var message = messages[code]; 250 message = format(message, args); 251 return message; 252 } 253 function format(text, args) { 254 var length = args.length; 255 for (var i = 0; i < length; i++) { 256 text = text.replace(new RegExp("\{" + i + "\}", "ig"), args[i]); 257 } 258 return text; 259 } 260 function parseArgs() { 261 var i = 0; 262 var commands = []; 263 var options = {}; 264 var args = process.argv.concat(); 265 args.splice(0, 2); 266 while (i < args.length) { 267 var s = args[i++]; 268 if (s.charAt(0) === '-') { 269 s = s.slice(s.charAt(1) === '-' ? 2 : 1).toLowerCase(); 270 if (!args[i] || args[i].charAt(0) == '-') { 271 options[s] = true; 272 } 273 else { 274 options[s] = args[i++] || ""; 275 } 276 } 277 else { 278 commands.push(s); 279 } 280 } 281 if (commands.length > 0) { 282 options.command = commands[0]; 283 if (commands.length > 1 && file.isDirectory(commands[1])) { 284 options.projectDir = commands[1]; 285 } 286 } 287 if (options.projectDir == null) { 288 options.projectDir = process.cwd(); 289 } 290 else { 291 var absPath = file.joinPath(process.cwd(), options.projectDir); 292 if (file.isDirectory(absPath)) { 293 options.projectDir = absPath; 294 } 295 } 296 options.projectDir = file.joinPath(options.projectDir, "/"); 297 return options; 298 } 299 function compareVersion(v1, v2) { 300 return versionToNumber(v1) - versionToNumber(v2); 301 function versionToNumber(v) { 302 var numbers = v.split(".").map(function (n) { 303 try { 304 return parseInt(n) || 0; 305 } 306 catch (e) { 307 return 0; 308 } 309 }); 310 var total = 0; 311 numbers.forEach(function (n, i) { 312 total += n * Math.pow(0.01, i); 313 }); 314 return total; 315 } 316 } 317 var file; 318 (function (file) { 319 var charset = "utf-8"; 320 /** 321 * 指定路径的文件或文件夹是否存在 322 */ 323 function exists(path) { 324 path = escapePath(path); 325 return FS.existsSync(path); 326 } 327 file.exists = exists; 328 /** 329 * 转换本机路径为Unix风格路径。 330 */ 331 function escapePath(path) { 332 if (!path) 333 return ""; 334 return path.split("\").join("/"); 335 } 336 file.escapePath = escapePath; 337 /** 338 * 读取文本文件,返回打开文本的字符串内容，若失败，返回"". 339 * @param path 要打开的文件路径 340 */ 341 function read(path, ignoreCache) { 342 if (ignoreCache === void 0) { ignoreCache = false; } 343 path = escapePath(path); 344 try { 345 var text = FS.readFileSync(path, charset); 346 text = text.replace(/^uFEFF/, ''); 347 } 348 catch (err0) { 349 return ""; 350 } 351 return text; 352 } 353 file.read = read; 354 /** 355 * 连接路径,支持传入多于两个的参数。也支持"../"相对路径解析。返回的分隔符为Unix风格。 356 */ 357 function joinPath(dir) { 358 var filename = []; 359 for (var _i = 1; _i < arguments.length; _i++) { 360 filename[_i - 1] = arguments[_i]; 361 } 362 var path = Path.join.apply(null, arguments); 363 path = escapePath(path); 364 return path; 365 } 366 file.joinPath = joinPath; 367 function isDirectory(path) { 368 path = escapePath(path); 369 try { 370 var stat = FS.statSync(path); 371 } 372 catch (e) { 373 return false; 374 } 375 return stat.isDirectory(); 376 } 377 file.isDirectory = isDirectory; 378 /** 379 * 获取指定文件夹下的文件或文件夹列表，不包含子文件夹内的文件。 380 * @param path 要搜索的文件夹 381 * @param relative 是否返回相对路径，若不传入或传入false，都返回绝对路径。 382 */ 383 function getDirectoryListing(path, relative) { 384 if (relative === void 0) { relative = false; } 385 path = escapePath(path); 386 try { 387 var list = FS.readdirSync(path); 388 } 389 catch (e) { 390 return []; 391 } 392 var length = list.length; 393 if (!relative) { 394 for (var i = length - 1; i >= 0; i--) { 395 if (list[i].charAt(0) == ".") { 396 list.splice(i, 1); 397 } 398 else { 399 list[i] = joinPath(path, list[i]); 400 } 401 } 402 } 403 else { 404 for (i = length - 1; i >= 0; i--) { 405 if (list[i].charAt(0) == ".") { 406 list.splice(i, 1); 407 } 408 } 409 } 410 return list; 411 } 412 file.getDirectoryListing = getDirectoryListing; 413 /** 414 * 获取路径的文件名(不含扩展名)或文件夹名 415 */ 416 function getFileName(path) { 417 if (!path) 418 return ""; 419 path = escapePath(path); 420 var startIndex = path.lastIndexOf("/"); 421 var endIndex; 422 if (startIndex > 0 && startIndex == path.length - 1) { 423 path = path.substring(0, path.length - 1); 424 startIndex = path.lastIndexOf("/"); 425 endIndex = path.length; 426 return path.substring(startIndex + 1, endIndex); 427 } 428 endIndex = path.lastIndexOf("."); 429 if (endIndex == -1 || isDirectory(path)) 430 endIndex = path.length; 431 return path.substring(startIndex + 1, endIndex); 432 } 433 file.getFileName = getFileName; 434 })(file || (file = {})); 435 function getLanguage() { 436 var selector = process['mainModule'].filename; 437 var languageXML = file.escapePath(file.joinPath(Path.dirname(selector), '../locales/language.xml')); 438 if (file.exists(languageXML)) { 439 var xml = file.read(languageXML); 440 var lang = /<language>([w_]*)</language>/.exec(xml); 441 if (lang) { 442 var localParts = lang[1].split('_'); 443 if (localParts.length >= 1) { 444 language = localParts[0]; 445 } 446 } 447 } 448 if (!language || language != "zh") { 449 language = "en"; 450 } 451 } 452 entry();
这个里面其他都不用关心，最后就是到了executeVersion函数里面。
就是require(bin);//bin:/Users/UserName/Library/Application Support/Egret/engine/5.3.7/tools/bin/egret
而这个就是egret就是引擎下面的egret文件，
我们进去看，其实就一句话：
require('../Entry.js').executeCommandLine(process.argv.slice(2))
即包含了../Entry.js，然后执行返回对象的executeCommandLine(process.argv.slice(2))。
这就真的进入了引擎的Entry.js文件，执行执行命令行函数了。
所以就是从这里进入了引擎代码里面了，接下来就去看引擎代码就好啦。