Shutdown / restart computer

The code example allows the user to choose between shutting down or restarting their computer. The program prompts the user for input and uses a switch statement to execute the corresponding system command based on the user’s choice.

Code Example

#include <iostream>
#include <cstdlib> // Include the cstdlib header for the system() function
using namespace std;

// Function prototypes
void shutdownComputer();
void restartComputer();
void handleInvalidInput();

int main() {
    int n;

    // Prompt the user for input
    cout << "Press 1 to shut down the computer or 2 to restart it: ";
    cin >> n;

    // Handle user input using a switch statement
    switch (n) {
        case 1: 
            shutdownComputer();
            break;
        case 2: 
            restartComputer();
            break;
        default:
            handleInvalidInput();
            break;
    }

    return 0;
}

// Function to shut down the computer
void shutdownComputer() {
    cout << "System shutdown after 10 seconds." << endl;
    system("c:\\windows\\system32\\shutdown /s /t 10 \n");
}

// Function to restart the computer
void restartComputer() {
    cout << "System restart after 10 seconds." << endl;
    system("c:\\windows\\system32\\shutdown /r /t 10 \n");
}

// Function to handle invalid input
void handleInvalidInput() {
    cout << "Incorrect input. Please enter 1 to shut down or 2 to restart the computer." << endl;
}

Code Explanation

Function Prototypes

void shutdownComputer();
void restartComputer();
void handleInvalidInput();

• Function prototypes are declared here. They inform the compiler about the functions shutdownComputer(), restartComputer(), and handleInvalidInput() before their actual definitions.

Main Function

int main() {
    int n;

    // Prompt the user for input
    cout << "Press 1 to shut down the computer or 2 to restart it: ";
    cin >> n;

    // Handle user input using a switch statement
    switch (n) {
        case 1: 
            shutdownComputer();
            break;
        case 2: 
            restartComputer();
            break;
        default:
            handleInvalidInput();
            break;
    }

    return 0;
}

• int main(): The main function where the execution of the program begins.
• int n;: Declares an integer variable n to store the user’s input.
• cout << "Press 1 to shut down the computer or 2 to restart it: ";: Prompts the user to enter 1 or 2.
• cin >> n;: Reads the user’s input and stores it in variable n.

The switch statement evaluates the value of n:

• case 1: If the user enters 1, the shutdownComputer() function is called.
• case 2: If the user enters 2, the restartComputer() function is called.
• default: If the user enters any other value, the handleInvalidInput() function is called.

Shutdown Function

void shutdownComputer() {
    cout << "System shutdown after 10 seconds." << endl;
    system("c:\\windows\\system32\\shutdown /s /t 10 \n");
}

• void shutdownComputer(): Defines a function that prints a message indicating that the system will shut down in 10 seconds.
• cout << "System shutdown after 10 seconds." << endl;: Outputs the shutdown message.
• system("c:\\windows\\system32\\shutdown /s /t 10 \n");: Executes the system command to shut down the computer after 10 seconds.

Restart Function

void restartComputer() {
    cout << "System restart after 10 seconds." << endl;
    system("c:\\windows\\system32\\shutdown /r /t 10 \n");
}

• void restartComputer(): Defines a function that prints a message indicating that the system will restart in 10 seconds.
• cout << "System restart after 10 seconds." << endl;: Outputs the restart message.
• system("c:\\windows\\system32\\shutdown /r /t 10 \n");: Executes the system command to restart the computer after 10 seconds.

Invalid Input Handling Function

void handleInvalidInput() {
    cout << "Incorrect input. Please enter 1 to shut down or 2 to restart the computer." << endl;
}

• void handleInvalidInput(): Defines a function that prints a message indicating that the input is incorrect.
• cout << "Incorrect input. Please enter 1 to shut down or 2 to restart the computer." << endl;: Outputs the error message prompting the user to enter a valid option.

Output

Let’s consider the different scenarios based on user input:

User inputs 1:

Press 1 to shut down the computer or 2 to restart it: 1
System shutdown after 10 seconds.

User inputs 2:

Press 1 to shut down the computer or 2 to restart it: 2
System restart after 10 seconds.

User inputs an invalid number (e.g., 3):

Press 1 to shut down the computer or 2 to restart it: 3
Incorrect input. Please enter 1 to shut down or 2 to restart the computer.