# File sample/test2.rb, line 16
def main
  pghost = nil
  pgport = nil
  pgoptions = nil
  pgtty = nil
  dbname = ENV['USER'] 
  begin
    conn = PGconn.connect(pghost,pgport,pgoptions,pgtty,dbname)
  rescue PGError
    printf(STDERR, "Connection to database '%s' failed.\n",dbname)
    exit(2)
  end
  begin
    res = conn.exec("LISTEN TBL2")
  rescue PGError
    printf(STDERR, "LISTEN command failed\n")
    exit(2)
  end
  res.clear
  while 1
    notify = conn.get_notify
    if (notify)
      printf(STDERR,"ASYNC NOTIFY '%s' from backend pid '%d' received\n",notify[0],notify[1])
      break
    end
  end
end