Method: Rex::IO::Stream#write

Defined in:
lib/rex/io/stream.rb

#write(buf, opts = {}) ⇒ Object

This method writes the supplied buffer to the stream. This method intelligent reduces the size of supplied buffers so that ruby doesn’t get into a potential global thread blocking state when used on blocking sockets. That is, this method will send the supplied buffer in chunks of, at most, 32768 bytes.



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# File 'lib/rex/io/stream.rb', line 35

def write(buf, opts = {})
  total_sent   = 0
  total_length = buf.length
  block_size   = 32768

  begin
    while( total_sent < total_length )
      s = Rex::ThreadSafe.select( nil, [ fd ], nil, 0.2 )
      if( s == nil || s[0] == nil )
        next
      end
      data = buf[total_sent, block_size]
      sent = fd.write_nonblock( data )
      if sent > 0
        total_sent += sent
      end
    end
  rescue ::Errno::EAGAIN, ::Errno::EWOULDBLOCK
    # Sleep for a half a second, or until we can write again
    Rex::ThreadSafe.select( nil, [ fd ], nil, 0.5 )
    # Decrement the block size to handle full sendQs better
    block_size = 1024
    # Try to write the data again
    retry
  rescue ::IOError, ::Errno::EPIPE
    return nil
  end

  total_sent
end