We know that there are two types of node modules: one is the core module (system module), a file module (custom module or third-party modules) The following briefly node inside those core modules.
First, the difference between the core module and file module
The core module consists of module Node.js Platform, also known as system module.
The core module import rules: (.) Is not a two-dot (..) or the start point and the identifier of the oblique rod (/).
var fs=require("fs")
File module: (.) Import rules to a two-dot (..) and the point or slash (/) start identifier
var hi =require("./hi")
Note: We usually import module will be stored in node_modules folder.
Two, os (operating system) kernel module
os Module provides the operating system-related use
Detailed NodeJs official Chinese documents address os module methods: http://nodejs.cn/api/os.html , here I simply talk
os.js
the require OS = const ( 'OS' ); // os.hostname () method returns the name of the host operating system as a string. console.log ( 'host name' + os.hostname ()); // os.cpus () method returns an array of objects containing information for each logical CPU core. console.log ( 'native the CPU' + os.cpus ()); // operating system platform os.platform () method returns a string that specifies Node.js compile time. console.log ( 'native operating system platform' + os.platform ()); // os.type () method returns a string, returns the name of the operating system. console.log ( 'native operating system:' + os.type ())
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Three: path (path) core modules
path Module provides a tool for processing the file path and directory path used.
For more modular approach path of NodeJs official Chinese documents Address: http://nodejs.cn/api/path.html
path.js
the require path = const ( 'path' ); var testData = 'E: /travel/index.html' ; // path.basename () method returns the last part of the path, the console.log (path.basename (testData)); // path.dirname () method returns the name of the directory path, i.e. removing the last part of the path of all the console.log (path.dirname (testData)); // path.extname () method returns the path of extension, from the last appears. (period) character string to the end of the last part of the path. console.log (path.extname (testData));
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Four, URL core module
url Module for processing and analysis URL.
Detailed NodeJs official Chinese document modular approach url address: http://nodejs.cn/api/url.html
url.js
the require URL = const ( 'URL' ); var Data = 'HTTP:? = //itcat.cn name Age = 22 is John Doe &' ; the console.log ( 'second default parameter False -' , url.parse (Data )); the console.log ( 'the second parameter to true -', url.parse (Data, to true )); the console.log ( 'the second parameter to true -', url.parse (Data, to true ) .query) ;
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Five, fs (file operation) core modules
fs Module provides an API, is used to mimic the function of the POSIX standard way to interact with the file system.
Detailed NodeJs official Chinese documents address methods modules fs: http://nodejs.cn/api/fs.html
About fs I have a simple application before, and now say again in this or next
fs.js, write data to the a.txt
var FS = the require ( 'FS' ); fs.writeFile ( './data/a.txt', 'Happy birthday country seventy, Happy Day everyone', function (ERR) { IF (ERR) { the console.log ( 'write failed " ); return ; } the else { the console.log ( ' write success' ); } });
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Six, http core module
http module provides an API, for use HTTP server and client
Detailed NodeJs official Chinese documents address methods modules fs: http://nodejs.cn/api/http.html
http.js
// 1. Load the core module http var http = the require ( 'http' ); // 2. Create a Web server http.createServer () method // returns a Server instance var Server = http.createServer (); // 3. registration request request event // when a client requests come, it will automatically trigger server request request event, and then perform the second argument: the callback handler server.on ( 'request', function (REQ, RES) { Console .log ( 'receiving the client's request, the request address is:' + req.url); the console.log ( 'received a request from a client, a request header address information (objects) are:' + req.headers); Console. log ( 'client receives the request, the request header address information (array) is:' + req.rawHeaders); the console.log ( 'received a request from a client, HTTP version request address is:' +req.httpVersion); the console.log ( 'receiving the client's request, the request is:' + req.method); the console.log ( 'I am requesting client address:' , req.socket.remoteAddress, REQ. socket.remotePort) // send a response content (res), res.setHeader () response data to solve distortion res.setHeader ( 'the content-the Type', 'text / HTML; charset = UTF-. 8' ); // The different url in response to different data var URL = req.url; IF (URL === '/' ) { res.end ( "Baidu, you know, <a href='http://www.baidu.com'> Baidu </a> " ); } the else IF (URL === '/ Login' ) { res.end ( 'the this IS Login Pages') }else if(URL === '/ Products' ) { var Products = [{ name: 'apple X-' , . price: 8888 }, { name: 'Pineapple X-' , . price: 5000 }, { name: 'peppers X-' , . price: 1999 } ] // NOTE: in response to the contents of only binary data or string // Therefore numbers, objects, arrays, and other required Boolean transformed. res.end (the JSON.stringify (Products)) } the else { // res.end () End response data res.end ( '404 Not Found.') } }) // 4. bound port number, the server starts server.listen (3000, function () { the console.log ( 'server starts successfully, can be accessed by http://127.0.0.1:3000/ ' ); })
Run, and visit the website
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In addition, nodejs inside the core module more than that, as the other documents we can go to the official website NodejsAPI View: http://nodejs.cn/api/