Receive and Send Flags

You can specify option flags with the lrs_send and lrs_receive functions:

You can set the following flags options:

Peek at the incoming data. The data is copied into the buffer but is not removed from the input queue.(lrs_receive only)
Don't include routing information in the message. This is only meaningful with output operations (lrs_send only), and is usually only used for diagnostic or routing programs.
Send or receive out-of-band (OOB) data. OOB data is an independent transmission that can be sent along with each pair of receive-send streams. OOB data may be delivered independently of the regular data, so it does not interrupt the normal stream. It is often used for urgent messages.