#include <errno.h>
#include <signal.h>
#include <stdio.h>

main () {
  int len;
  FILE *f = fopen ("/tmp/hello", "w");
  signal (SIGPIPE, SIG_IGN);
  while (1) {
    /* len = write (1, "hello\n", 6); */
    len = fwrite ("hello\n", 1, 6, stdout);
    fprintf (f, "fwrite=%d ferror=%d errno=%d\n", len, ferror (stdout), errno);
    fflush (f);
    sleep (1);
  }
}