# Recent changes log
my $RC_FILE = "$TOPDIR/wikidb/rclog";
open(TAIL, "tail -f -n 0 $RC_FILE |");

my $rin = '';
vec($rin, fileno(TAIL), 1) = 1;
while (1) {
  # Check for file input
  select(my $rout = $rin, undef, undef, undef);
  if (vec($rout, fileno(TAIL), 1)) {
    ...;
  }
}