#include <stdio.h>
#include <signal.h>
#include <setjmp.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#define TRUE               1
#define FALSE              0

#define CHECK_TIMEOUT      10

typedef void Sigfunc(int);

/* Private variables */
static sigjmp_buf timeout;
static void connection_timeout(int);
Sigfunc *signal(int signo, Sigfunc *func);
void set_alarm_handler(void *func);
int action(void);
void checker(void);

static void connection_timeout(int sig) {
  
  siglongjmp(timeout, TRUE);
  
}

/**
 * Replace the standard signal() function, with a more reliable
 * using sigaction. From W. Richard Stevens' "Advanced Programming
 * in the UNIX Environment"
 */
Sigfunc *signal(int signo, Sigfunc *func) {

  struct sigaction act, oact;

  act.sa_handler = func;
  sigemptyset(&act.sa_mask);
  act.sa_flags = 0;
  if (signo == SIGALRM) {
#ifdef  SA_INTERRUPT
    act.sa_flags |= SA_INTERRUPT;   /* SunOS */
#endif
  } else {
#ifdef  SA_RESTART
    act.sa_flags |= SA_RESTART;             /* SVR4, 44BSD */
#endif
  }
  if (sigaction(signo, &act, &oact) < 0)
      return(SIG_ERR);

  return(oact.sa_handler);

}


/**
 * Set a handler for the alarm signal,
 * SIGALRM using sigaction.
 */
void set_alarm_handler(void *func) {

  struct sigaction sa;

  sa.sa_handler= func;
  sa.sa_flags= 0;
  sigemptyset(&sa.sa_mask);
  sigaction(SIGALRM, &sa, NULL);

}

int action(void) {

  int i;
  int fd;
  char buf[1025];
  
  fd= open("/home/chopp/isos/Mandrake82-cd1-inst.i586.iso", O_RDONLY);

  if ( fd < 0 ) {

    return -1;

  }
    
  for ( i = 0; i < 1024000; i ++ ) {

    if( read(fd, buf, 1024) != 1024 ) {
      
      return -1;

    }
  }

  close(fd);
  return 1;

}

void checker(void) {

  int action_return = 0;

  if ( sigsetjmp(timeout, TRUE) ) {
    goto label_timeout;
  }

  /* Set a timeout handler and activate the timer */
  set_alarm_handler(connection_timeout);
  alarm(CHECK_TIMEOUT);

  action_return = action();
  alarm(0);

  if ( action_return ) {

    printf("Exiting successfully!\n");

  } else {

    printf("Exiting non successfully!\n");

  }

  return;
  
 label_timeout:
  
  printf("Timeout occured!\n");
 
  return;
}

int main () {

  checker();

}