Shut Down the machines using c programming:

For windows operating system:

#include "stdio.h"
#include "stdlib.h"

main()
{
char ch;

printf("Do you want to shutdown your computer now (y/n)n");
scanf("%c",&ch);

if (ch == 'y' || ch == 'Y')
system("C:\WINDOWS\System32\shutdown -s");

return 0;
}

For windows 7 operating system

#include "stdio.h"
#include "stdlib.h"

main()
{
char ch;

printf("Do you want to shutdown your computer now (y/n)n");
scanf("%c",&ch);

if (ch == 'y' || ch == 'Y')
system("C:\WINDOWS\System32\shutdown /s");

return 0;
}

For unix/linux operating system:

#include "stdio.h"

int main()
{
system("shutdown -P now");
return 0;
}