• Definition: Angular CLI is a command-line interface tool for Angular, a popular framework for building web applications. It helps developers scaffold, develop, test, and deploy Angular applications efficiently.
• Function: Provides commands to create, manage, and deploy Angular applications, facilitating tasks such as project setup, file generation, and configuration management.
• Components:

   * '''ng new''': Generates a new Angular application.
   * '''ng generate''': Creates new components, services, modules, and other Angular constructs.
   * '''ng serve''': Serves the application locally for development and testing.
   * '''ng build''': Builds the application for deployment.
   * '''ng test''': Runs unit tests.
   * '''ng e2e''': Runs end-to-end tests.

• Features:

   * '''Project Scaffolding''': Quickly sets up a new Angular project with best practices.
   * '''Code Generation''': Automates the creation of Angular components, services, and other code structures.
   * '''Development Server''': Provides a live-reload development server.
   * '''Testing Tools''': Integrates unit and end-to-end testing capabilities.
   * '''Build Optimization''': Produces optimized builds for deployment.

• Usage: Ideal for developers who want to streamline the process of building, testing, and deploying Angular applications.

• Creating a new Angular project:

   ```bash
   ng new my-angular-app
   ```

• Generating a new component:

   ```bash
   ng generate component my-component
   ```

• Serving the application locally:

   ```bash
   ng serve
   ```

• Building the application for production:

   ```bash
   ng build --prod
   ```

• Running unit tests:

   ```bash
   ng test
   ```

• Using Angular CLI in a Python script:

   ```python
   import subprocess

 def run_angular_cli_command(command):
     result = subprocess.run(command, capture_output=True, text=True)
     print(result.stdout)
     if result.stderr:
         print(f"Error: {result.stderr}")

 # Example usage: create a new Angular project
 run_angular_cli_command(['ng', 'new', 'my-angular-app'])
 ```

• Using Angular CLI in a Java program:

   ```java
   import java.io.BufferedReader;
   import java.io.InputStreamReader;

 public class AngularCliExample {
     public static void runAngularCliCommand(String[] command) {
         try {
             Process process = new ProcessBuilder(command).start();
             BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
             String line;
             while ((line = reader.readLine()) != null) {
                 System.out.println(line);
             }
             reader.close();
             int exitCode = process.waitFor();
             if (exitCode != 0) {
                 BufferedReader errorReader = new BufferedReader(new InputStreamReader(process.getErrorStream()));
                 while ((line = errorReader.readLine()) != null) {
                     System.err.println("Error: " + line);
                 }
                 errorReader.close();
             }
         } catch (Exception e) {
             e.printStackTrace();
         }
     }

     public static void main(String[] args) {
         // Example usage: create a new Angular project
         runAngularCliCommand(new String[]{"ng", "new", "my-angular-app"});
     }
 }
 ```

• Angular CLI: A command-line tool for Angular that streamlines the process of building, testing, and deploying Angular applications. It provides commands for project scaffolding, code generation, development server, testing, and build optimization. Angular CLI enhances developer productivity by automating repetitive tasks and ensuring best practices.