rem: {  if (fflush (stdout) < 0) error (EXIT_FAILURE, errno, _("write error"));  SETVBUF (stdout, NULL, _IONBF, 0); tail_forever (F, n_files, sleep_interval); }
add: tail_forever (F, n_files, sleep_interval);
context: main (int argc, char **argv){  enum header_mode header_mode = multiple_files;  int exit_status = 0;  /* If from_start, the number of items to skip before printing; otherwise,     the number of items at the end of the file to print.  Although the type     is signed, the value is never negative.  */  off_t n_units = DEFAULT_N_LINES;  int n_files;  char **file;  struct File_spec *F;  int i;  /* The number of seconds to sleep between iterations.     During one iteration, every file name or descriptor is checked to     see if it has changed.  */  double sleep_interval = 1.0;  program_name = argv[0];  setlocale (LC_ALL, "");  bindtextdomain (PACKAGE, LOCALEDIR);  textdomain (PACKAGE);  atexit (close_stdout);  have_read_stdin = 0;  {    int fail;    if (parse_obsolescent_option (argc,				  (const char *const *) argv,				  &n_units, &fail))      {	if (fail)	  exit (EXIT_FAILURE);	optind = 2;      }    else      {	parse_options (argc, argv, &n_units, &header_mode, &sleep_interval);      }  }  /* To start printing with item N_UNITS from the start of the file, skip     N_UNITS - 1 items.  `tail -n +0' is actually meaningless, but for Unix     compatibility it's treated the same as `tail -n +1'.  */  if (from_start)    {      if (n_units)	--n_units;    }  n_files = argc - optind;  file = argv + optind;  if (n_files == 0)    {      static char *dummy_stdin = "-";      n_files = 1;      file = &dummy_stdin;    }  F = (struct File_spec *) xmalloc (n_files * sizeof (F[0]));  for (i = 0; i < n_files; i++)    F[i].name = file[i];  if (header_mode == always      || (header_mode == multiple_files && n_files > 1))    print_headers = 1;  for (i = 0; i < n_files; i++)    exit_status |= tail_file (&F[i], n_units);  if (forever)    {      /* This fflush appears to be required only on Solaris2.7.  */      if (fflush (stdout) < 0)	error (EXIT_FAILURE, errno, _("write error"));      SETVBUF (stdout, NULL, _IONBF, 0);      tail_forever (F, n_files, sleep_interval);    }  if (have_read_stdin && close (STDIN_FILENO) < 0)    error (EXIT_FAILURE, errno, "-");  exit (exit_status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);}