linux下c语言关机程序

/* Offtimer.c.For auto halt. */
#include <time.h>
#include <stdlib.h>
#include <unistd.h>
#define DELAY 60/* Time of sleeping */
int main()
{
  time_t now;
  struct tm *p;
  
  while(1)
  {
  now = time(NULL);
  sleep(DELAY);/* To reduce cpu occupation */
  p = localtime(&now);
  if ((p->tm_hour = 14) && (p->tm_min >= 30))/ *This means the system will halt after 14:30 or 14:31 */
  system("poweroff"); / *'poweroff' is the command in Red Flag Linux
Desktop 5.0 to turn off the computer.To do this you should be root. */
  }
  return 0;
}
引用gcc编译，另外需要有root用户的权利才能行。