#include <stdio.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>
#include <stdlib.h>

#define MAX_LENGTH 10


char *buf[MAX_LENGTH];


static void sigact_handler (int sig, siginfo_t *siginfo, void *context)
{

  read(0, buf, MAX_LENGTH);
  // printf("Read\n %d");

  write(1, buf, MAX_LENGTH);
  // printf("Written\n\n");
  printf("pid: %ld\nuid: %ld\n\n", (long) siginfo->si_pid, (long) siginfo->si_uid);
}

int main (void)
{
  alarm(10);
  printf("Set alarm.\nEnter a string:\n");

  struct sigaction mysigact;

  // set handler
  mysigact.sa_sigaction = &sigact_handler;

  // says do not use sa_handler field, use the above sa_sigaction field
  // sa_sigaction takes more arguments
  mysigact.sa_flags = SA_RESTART; // switching between SA_SIGINFO and SA_RESTART

  if (sigaction (SIGALRM, &mysigact, NULL) < 0)
  {
    perror("sigalrm");
    return 1;
  }

  while(1) sleep(10);

  return 0;
}