{"id":1691,"date":"2025-03-25T20:10:07","date_gmt":"2025-03-25T14:40:07","guid":{"rendered":"http:\/\/codeforgeek.com\/?p=1691"},"modified":"2025-03-25T20:37:40","modified_gmt":"2025-03-25T15:07:40","slug":"command-line-application-nodejs","status":"publish","type":"post","link":"https:\/\/codeforgeek.com\/command-line-application-nodejs\/","title":{"rendered":"Develop Command Line Applications Using Node.js & SpeedTest.net"},"content":{"rendered":"\n

Node.js provides powerful utilities to develop command-line applications. Popular tools like Express Generator<\/strong> and Nodemon <\/strong>are examples of command-line applications built with Node.js. <\/p>\n\n\n\n

In this tutorial, we’ll learn how to use Node.js to create command-line utilities and build a sample internet speed test application using the speedtest.net API<\/strong>.<\/p>\n\n\n\n

Getting Started with Command Line Applications<\/h2>\n\n\n\n

Command-line applications (CLIs) allow users to interact with programs through text commands in a terminal or console interface. Node.js makes it easy to create these applications with its built-in modules and npm ecosystem.<\/p>\n\n\n\n

Basic Hello World Command Line App:<\/h3>\n\n\n\n

Let’s start by creating a simple application that greets users by name. First, we’ll write code to print “Hello World” to the console:<\/p>\n\n\n

\nconsole.log("Hello World");\n<\/pre><\/div>\n\n\n
Save this code in a file named cli.js<\/strong> and run it using:<\/p>\n\n\n
\nnode cli.js\n<\/pre><\/div>\n\n\n
You’ll see “Hello World” printed in your console. But what if we want to pass a name as an argument? Let’s modify our code to accept input from the command line:<\/p>\n\n\n
\n#!\/usr\/bin\/env node\nconsole.log("Hello", process.argv[2]);\n<\/pre><\/div>\n\n\n
The first line #!\/usr\/bin\/env node<\/strong> is a shebang that tells the system this script should be executed with Node.js. The process.argv<\/strong> array contains command-line arguments, with the third element (index 2) being the first user-provided argument.<\/p>\n\n\n\n
Now when you run:<\/p>\n\n\n
\nnode cli.js Shahid\n<\/pre><\/div>\n\n\n
It will output: Hello Shahid<\/strong><\/p>\n\n\n\n
Making Script Globally Accessible:<\/h3>\n\n\n\n
To make your script accessible as a command from anywhere in your system, you need to create a package.json<\/strong> file:<\/p>\n\n\n
\n{\n  "name": "HelloWorld",\n  "version": "1.0.0",\n  "description": "A simple greeting CLI",\n  "author": "",\n  "license": "ISC",\n  "bin": {\n    "sayHello": "cli.js"\n  },\n  "dependencies": {}\n}\n<\/pre><\/div>\n\n\n
The bin <\/strong>field maps command names to the JavaScript files that should be executed when those commands are run. In this case, when users run sayHello<\/strong>, the system will execute cli.js<\/strong>.<\/p>\n\n\n\n
Install your package globally:<\/p>\n\n\n
\nnpm install -g\n<\/pre><\/div>\n\n\n
Now you can run your command from anywhere:<\/p>\n\n\n
\nsayHello Shahid\n<\/pre><\/div>\n\n\n
Building Speedtest CLI Application<\/h2>\n\n\n\n
Now let’s create a more useful application: a command-line tool to test internet speed using the speedtest.net API.<\/p>\n\n\n\n
Setting Up the Project:<\/h3>\n\n\n\n
First, create a new directory for your project and initialize it:<\/p>\n\n\n
\nmkdir speedtest-cli\ncd speedtest-cli\nnpm init\n<\/pre><\/div>\n\n\n
Install the required dependencies:<\/p>\n\n\n
\nnpm install chalk progress speedtest-net --save\n<\/pre><\/div>\n\n\n
These packages will help us:<\/p>\n\n\n\n
    \n
  • speedtest-net<\/strong>: Wrapper for the speedtest.net API<\/li>\n\n\n\n
  • progress<\/strong>: Creates progress bars in the terminal<\/li>\n\n\n\n
  • chalk<\/strong>: Adds colors to terminal output<\/li>\n<\/ul>\n\n\n\n
    Create a package.json <\/strong>file:<\/p>\n\n\n
    \n{\n  "name": "speedtest-cli",\n  "version": "1.0.0",\n  "description": "Command line tool to test internet speed",\n  "main": "index.js",\n  "bin": {\n    "speedtest": "index.js"\n  },\n  "dependencies": {\n    "chalk": "^4.1.2",\n    "progress": "^2.0.3",\n    "speedtest-net": "^2.2.0"\n  },\n  "keywords": ["speedtest", "cli", "internet", "speed"],\n  "author": "",\n  "license": "ISC"\n}\n<\/pre><\/div>\n\n\n
    Creating Speedtest Application:<\/h3>\n\n\n\n
    Now let’s write the main application code in index.js<\/strong>:<\/p>\n\n\n
    \n#!\/usr\/bin\/env node\n\nconst speedTest = require('speedtest-net');\nconst ProgressBar = require('progress');\nconst chalk = require('chalk');\n\n\/\/ Create a progress bar utility function\nfunction createProgressBar(what) {\n  console.log(chalk.cyan(what));\n  return new ProgressBar('[:bar] :percent', {\n    complete: '=',\n    incomplete: ' ',\n    width: 40,\n    total: 100\n  });\n}\n\nasync function runSpeedTest() {\n  try {\n    console.log(chalk.yellow('Starting speed test...'));\n    console.log(chalk.dim('This may take up to 30 seconds\\n'));\n\n    \/\/ Create progress bars\n    const downloadBar = createProgressBar('Testing download speed');\n    const uploadBar = createProgressBar('Testing upload speed');\n    \n    \/\/ Run the test\n    const result = await speedTest({\n      acceptLicense: true,\n      acceptGdpr: true,\n      progress: (progress) => {\n        if (progress.type === 'download') {\n          downloadBar.update(progress.percent \/ 100);\n        } else if (progress.type === 'upload') {\n          uploadBar.update(progress.percent \/ 100);\n        }\n      }\n    });\n\n    \/\/ Display results\n    console.log('\\n' + chalk.green('\u2713') + ' Speed test completed!\\n');\n    console.log(chalk.cyan('Server:') + ' ' + result.server.name + ' (' + result.server.location + ', ' + result.server.country + ')');\n    console.log(chalk.cyan('Ping:') + ' ' + result.ping.latency.toFixed(2) + chalk.dim(' ms'));\n    console.log(chalk.cyan('Jitter:') + ' ' + result.ping.jitter.toFixed(2) + chalk.dim(' ms'));\n    console.log(chalk.cyan('Download:') + ' ' + (result.download.bandwidth \/ 125000).toFixed(2) + chalk.dim(' Mbps'));\n    console.log(chalk.cyan('Upload:') + ' ' + (result.upload.bandwidth \/ 125000).toFixed(2) + chalk.dim(' Mbps'));\n    \n  } catch (error) {\n    console.error(chalk.red('Error running speed test:'), error.message);\n    process.exit(1);\n  }\n}\n\n\/\/ Run the speed test\nrunSpeedTest();\n<\/pre><\/div>\n\n\n
    This code:<\/p>\n\n\n\n
      \n
    1. Imports the required modules<\/li>\n\n\n\n
    2. Creates a function to display progress bars<\/li>\n\n\n\n
    3. Defines an async function to run the speed test<\/li>\n\n\n\n
    4. Displays the results in a user-friendly format with colors<\/li>\n<\/ol>\n\n\n\n
      Installing and Using Speedtest CLI:<\/h3>\n\n\n\n
      Make the script executable:<\/p>\n\n\n
      \nchmod +x index.js\n<\/pre><\/div>\n\n\n
      Install it globally:<\/p>\n\n\n
      \nnpm install -g\n<\/pre><\/div>\n\n\n
      Now you can run your speed test from anywhere:<\/p>\n\n\n
      \nspeedtest\n<\/pre><\/div>\n\n\n
      Advanced CLI Development Techniques<\/h2>\n\n\n\n
      1. Using Commander.js for Complex CLIs:<\/h3>\n\n\n\n
      For more complex command-line applications, consider using the Commander.js library, which simplifies argument parsing and help documentation:<\/p>\n\n\n
      \n#!\/usr\/bin\/env node\nconst { program } = require('commander');\nconst speedTest = require('speedtest-net');\nconst chalk = require('chalk');\n\nprogram\n  .version('1.0.0')\n  .option('-s, --server <id>', 'Use a specific server')\n  .option('-j, --json', 'Output results as JSON')\n  .option('-v, --verbose', 'Show detailed progress')\n  .parse(process.argv);\n\nconst options = program.opts();\n\nasync function runTest() {\n  \/\/ Implementation using options\n}\n\nrunTest();\n<\/pre><\/div>\n\n\n
      2. Adding Interactive Elements with Inquirer.js:<\/h3>\n\n\n\n
      You can make your CLI more interactive using Inquirer.js:<\/p>\n\n\n
      \nconst inquirer = require('inquirer');\n\nasync function promptUser() {\n  const answers = await inquirer.prompt([\n    {\n      type: 'list',\n      name: 'testType',\n      message: 'What would you like to test?',\n      choices: ['Download & Upload', 'Download only', 'Upload only', 'Ping only']\n    }\n  ]);\n  \n  \/\/ Run the appropriate test based on user selection\n}\n<\/pre><\/div>\n\n\n
      3. Displaying Results with Tables:<\/h3>\n\n\n\n
      For structured data, you can use the cli-table3 <\/strong>package:<\/p>\n\n\n
      \nconst Table = require('cli-table3');\n\nfunction displayResults(results) {\n  const table = new Table({\n    head: ['Metric', 'Value', 'Unit'],\n    colWidths: [20, 10, 10]\n  });\n  \n  table.push(\n    ['Ping', results.ping.toFixed(2), 'ms'],\n    ['Download', results.download.toFixed(2), 'Mbps'],\n    ['Upload', results.upload.toFixed(2), 'Mbps']\n  );\n  \n  console.log(table.toString());\n}\n<\/pre><\/div>\n\n\n
      Conclusion<\/h2>\n\n\n\n
      We’ve learned how to develop command-line applications using Node.js, from basic argument handling to creating a full-featured internet speed test tool. Command-line utilities are incredibly useful for automation, development workflows, and system administration tasks.<\/p>\n\n\n\n
      The techniques covered in this tutorial can be applied to create various types of CLI applications, from simple scripts to complex tools with interactive features and rich output formatting.<\/p>\n\n\n\n
      For further exploration, consider checking out these libraries:<\/strong><\/p>\n\n\n\n
        \n
      • Commander.js –<\/strong> A complete solution for Node.js command-line interfaces<\/li>\n\n\n\n
      • Inquirer.js –<\/strong> For creating interactive command prompts<\/li>\n\n\n\n
      • Chalk – <\/strong>For terminal string styling<\/li>\n\n\n\n
      • Ora – <\/strong>Elegant terminal spinners<\/li>\n\n\n\n
      • Boxen – <\/strong>Create boxes in the terminal<\/li>\n<\/ul>\n\n\n\n
        With these tools and techniques, you can create professional-grade command-line applications that enhance your productivity and simplify complex tasks.<\/p>\n","protected":false},"excerpt":{"rendered":"
        Node.js provides powerful utilities to develop command-line applications. Popular tools like Express Generator and Nodemon are examples of command-line applications built with Node.js. In this tutorial, we’ll learn how to use Node.js to create command-line utilities and build a sample internet speed test application using the speedtest.net API. Getting Started with Command Line Applications Command-line […]<\/p>\n","protected":false},"author":1,"featured_media":33315,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_surecart_dashboard_logo_width":"180px","_surecart_dashboard_show_logo":true,"_surecart_dashboard_navigation_orders":true,"_surecart_dashboard_navigation_invoices":true,"_surecart_dashboard_navigation_subscriptions":true,"_surecart_dashboard_navigation_downloads":true,"_surecart_dashboard_navigation_billing":true,"_surecart_dashboard_navigation_account":true,"_uag_custom_page_level_css":"","footnotes":""},"categories":[14],"tags":[],"class_list":["post-1691","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-nodejs"],"blocksy_meta":[],"uagb_featured_image_src":{"full":["https:\/\/codeforgeek.com\/wp-content\/uploads\/2025\/03\/Develop-Command-Line-Applications.png",1000,600,false],"thumbnail":["https:\/\/codeforgeek.com\/wp-content\/uploads\/2025\/03\/Develop-Command-Line-Applications-150x150.png",150,150,true],"medium":["https:\/\/codeforgeek.com\/wp-content\/uploads\/2025\/03\/Develop-Command-Line-Applications-300x180.png",300,180,true],"medium_large":["https:\/\/codeforgeek.com\/wp-content\/uploads\/2025\/03\/Develop-Command-Line-Applications-768x461.png",768,461,true],"large":["https:\/\/codeforgeek.com\/wp-content\/uploads\/2025\/03\/Develop-Command-Line-Applications.png",1000,600,false],"1536x1536":["https:\/\/codeforgeek.com\/wp-content\/uploads\/2025\/03\/Develop-Command-Line-Applications.png",1000,600,false],"2048x2048":["https:\/\/codeforgeek.com\/wp-content\/uploads\/2025\/03\/Develop-Command-Line-Applications.png",1000,600,false]},"uagb_author_info":{"display_name":"Shahid","author_link":"https:\/\/codeforgeek.com\/author\/shahid\/"},"uagb_comment_info":0,"uagb_excerpt":"Node.js provides powerful utilities to develop command-line applications. Popular tools like Express Generator and Nodemon are examples of command-line applications built with Node.js. In this tutorial, we’ll learn how to use Node.js to create command-line utilities and build a sample internet speed test application using the speedtest.net API. Getting Started with Command Line Applications Command-line…","_links":{"self":[{"href":"https:\/\/codeforgeek.com\/wp-json\/wp\/v2\/posts\/1691","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/codeforgeek.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/codeforgeek.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/codeforgeek.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/codeforgeek.com\/wp-json\/wp\/v2\/comments?post=1691"}],"version-history":[{"count":0,"href":"https:\/\/codeforgeek.com\/wp-json\/wp\/v2\/posts\/1691\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/codeforgeek.com\/wp-json\/wp\/v2\/media\/33315"}],"wp:attachment":[{"href":"https:\/\/codeforgeek.com\/wp-json\/wp\/v2\/media?parent=1691"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/codeforgeek.com\/wp-json\/wp\/v2\/categories?post=1691"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/codeforgeek.com\/wp-json\/wp\/v2\/tags?post=1691"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}