Program to shutdown a system
Last Updated :
23 Jun, 2022
How to shutdown your computer in Linux and/or Windows?
The idea is to use system() in C. This function is used to invoke operating system commands from C program.
Linux OS:
C
// C program to shutdown in Linux
#include <stdio.h>
#include <stdlib.h>
int main()
{
// Running Linux OS command using system
system("shutdown -P now");
return 0;
}
//Java program to shut down the system with linux OS
import java.io.IOException;
import java.util.Scanner;
public class Shutdown_System
{
public static void main(String args[]) throws IOException
{
int sec=1;
String operatingSystem = System.getProperty("os.name");
System.out.println("Name of Operating System:"+operatingSystem);
if(operatingSystem.equals("Linux"))
{
Runtime runtime = Runtime.getRuntime();
Scanner s = new Scanner(System.in);
System.out.print("System will shut down after 1 second:");
Process proc = runtime.exec("shutdown -h -t "+sec);
System.exit(0);
}
else
{
System.out.println("Something went wrong.");
}
}
}
Windows OS: Shutdown/ Log off/ Restart a Windows OS
We will make use of system() from < stdlib.h > to perform a system operation with the help of a C program. To perform any of the afore-mentioned system operation code will be as follows:
C
//C program to shut down the system in Windows OS
#include <stdio.h>
#include <stdlib.h>
int main()
{
system("c:\\windows\\system32\\shutdown /i");
return 0;
}
//Java program to shutdoen the system after 5 seconds for windows OS
import java.io.*;
public class GFG
{
public static void main(String[] args)
{
Runtime runtime = Runtime.getRuntime();
try
{
System.out.println("System will shutdown after 5 seconds.");
runtime.exec("shutdown -s -t 5");
}
catch(IOException e)
{
System.out.println("Exception: " +e);
}
}
}
The argument to the system function is the path to OS and /i is one of the entity from the vast options available to us. To view the options, we run cmd and type:
C:\Users\User>shutdown
The shutdown command presents us with a list of options available for us.
These are : 
To perform different operations, we just replace the last "/path" in system() argument. The common operations are:
Shutdown
system("c:\\windows\\system32\\shutdown /s");Restart
system("c:\\windows\\system32\\shutdown /r");Logoff
system("c:\\windows\\system32\\shutdown /l");
Time Complexity: O(1), As program will directly execute the command through OS, time complexity will be O(1).
Space Complexity: O(1)