Ruby » Ruby master

 *               [, timeout]]]) -> array  or  nil

 *  Calls select(2) system call.

 *  It monitors given arrays of <code>IO</code> objects, waits one or more

 *  of <code>IO</code> objects ready for reading, are ready for writing,

 *  and have pending exceptions respectably, and returns an array that

 *  contains arrays of those IO objects.  It will return <code>nil</code>

 *  if optional <i>timeout</i> value is given and no <code>IO</code> object

 *  is ready in <i>timeout</i> seconds.

 *

 *  === Parameters

 *  read_array:: an array of <code>IO</code> objects that wait until ready for read

 *  write_array:: an array of <code>IO</code> objects that wait until ready for write

 *  error_array:: an array of <code>IO</code> objects that wait for exceptions

 *  timeout:: a numeric value in second

 *

 *  === Example

 *

 *      rp, wp = IO.pipe

 *      mesg = "ping "

 *      100.times {

 *        rs, ws, = IO.select([rp], [wp])

 *        if r = rs[0]

 *          ret = r.read(5)

 *          print ret

 *          case ret

 *          when /ping/

 *            mesg = "pong\n"

 *          when /pong/

 *            mesg = "ping "

 *          end

 *        end

 *        if w = ws[0]

 *          w.write(mesg)

 *        end

 *      }

 *

 *  <em>produces:</em>

 *

 *      ping pong

 *      ping pong

 *      ping pong

 *      (snipped)

 *      ping