write

The user may transmit data over the transport connection using write(S). The tirdwr module will pass data through to the transport provider. However, if a user attempts to send a zero-length data packet, which the STREAMS mechanism allows, tirdwr will discard the message. If the transport connection is aborted (for example, because the remote user aborts the connection using t_snddis), a STREAMS hangup condition will be generated on that Stream, and further write calls will fail and set errno to ENXIO. The user can still retrieve any available data after a hangup.