# File sample/psql.rb, line 455
def do_connect(settings, new_dbname)
  dbname = settings.db.db

  if !new_dbname
    printf(STDERR, "\\connect must be followed by a database name\n");
  else
    olddb = settings.db

    begin 
      printf("closing connection to database: %s\n", dbname);
      settings.db = PGconn.connect(olddb.host, olddb.port, "", "", new_dbname)
      printf("connecting to new database: %s\n", new_dbname)
      olddb.finish()
    rescue
      printf(STDERR, "%s\n", $!)
      printf("reconnecting to %s\n", dbname)
      settings.db = PGconn.connect(olddb.host, olddb.port,"", "", dbname)
    ensure
      settings.prompt = settings.db.db + PROMPT
    end
  end
end