{ "source": "doc/api/synopsis.md", "introduced_in": "v0.10.0", "miscs": [ { "textRaw": "Usage", "name": "Usage", "introduced_in": "v0.10.0", "type": "misc", "desc": "

node [options] [V8 options] [script.js | -e "script" | - ] [arguments]

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Please see the Command Line Options document for information about\ndifferent options and ways to run scripts with Node.js.

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Example

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An example of a web server written with Node.js which responds with\n'Hello World!':

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Commands displayed in this document are shown starting with $ or >\nto replicate how they would appear in a user's terminal.\nDo not include the $ and > character they are there to\nindicate the start of each command.

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There are many tutorials and examples that follow this\nconvention: $ or > for commands run as a regular user, and #\nfor commands that should be executed as an administrator.

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Lines that don’t start with $ or > character are typically showing\nthe output of the previous command.

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Firstly, make sure to have downloaded and installed Node.js.\nSee this guide for further install information.

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Now, create an empty project folder called projects, navigate into it:\nProject folder can be named base on user's current project title but\nthis example will use projects as the project folder.

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Linux and Mac:

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$ mkdir ~/projects\n$ cd ~/projects\n
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Windows CMD:

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> mkdir %USERPROFILE%\\projects\n> cd %USERPROFILE%\\projects\n
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Windows PowerShell:

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> mkdir $env:USERPROFILE\\projects\n> cd $env:USERPROFILE\\projects\n
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Next, create a new source file in the projects\n folder and call it hello-world.js.

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In Node.js it is considered good style to use\nhyphens (-) or underscores (_) to separate\n multiple words in filenames.

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Open hello-world.js in any preferred text editor and\npaste in the following content.

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const http = require('http');\n\nconst hostname = '127.0.0.1';\nconst port = 3000;\n\nconst server = http.createServer((req, res) => {\n  res.statusCode = 200;\n  res.setHeader('Content-Type', 'text/plain');\n  res.end('Hello World!\\n');\n});\n\nserver.listen(port, hostname, () => {\n  console.log(`Server running at http://${hostname}:${port}/`);\n});\n
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Save the file, go back to the terminal window enter the following command:

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$ node hello-world.js\n
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An output like this should appear in the terminal to indicate Node.js\nserver is running:

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Server running at http://127.0.0.1:3000/\n
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Now, open any preferred web browser and visit http://127.0.0.1:3000.

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If the browser displays the string Hello, world!, that indicates\nthe server is working.

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Many of the examples in the documentation can be run similarly.

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