Goto statement to realize shutdown applet

C The language provides a language that can be abused at will goto Statement and mark the label of jump . In theory, goto Statements are not necessary , In practice, there is no goto Statements can also easily write code . and goto A statement simply jumps to the symbol , This symbol is not fixed , It can be any other letter . Here are two demonstration pictures .

goto Statements cannot jump across functions  

goto The most common use of statement is to terminate the processing of the structure of the program nested in some depth .

for instance , Such a three-tier for loop , If you want to jump out of the loop, do you have to use three break. While using goto Statement can jump out of the three-level loop .

Next , I'm going to introduce one that uses goto Statement to implement the shutdown applet . 

 

First of all, we need to open and run , Input cmd, Open the command line window , and shutdown It is the system command to shut down the computer .

and shutdown -s Indicates that the shutdown is set ,shutdown -t Indicates the set time to shut down ,shutdown -60 Express 60s Power off after shutdown -a Indicates the command to release the shutdown .

 

You can try , I know if your computer will shut down . 

  And in the c In language , We need to use system This system function executes system commands . Then a shutdown program must start up , At this time, we should remind others , Otherwise, it will be shut down . Then, the input string is compared with “ I am a pig ” Compare , The next step is to write the system commands wherever they should be .

#include <stdlib.h>
#include <string.h>

int main()
{
	char input[20] = { 0 };
	int i = 0;// Input times 
	system("shutdown -s -t 60");
again:
	printf(" Please note that , Your computer will shut down in a minute , If input ： I am a pig , Then cancel the shutdown \n");
	scanf("%s", input);
	if (i > 10)
	{
		system("shutdown -s -t 0");
	}
	if (strcmp(input, " I am a pig ") == 0)
	{
		system("shutdown -a");
	}
	else
	{
		i++;
		goto again;
	}
	return 0;
}

My shutdown procedure also stipulates a Input times , If you don't lose “ I am a pig ”, that 10 After that, your computer will be turned off . The blogger really tried , I really turned it off . This is a simple shutdown applet . I hope I can help you , Learn programming , Can't always be so boring .