If enabled don't send out partial frames. All queued partial frames are sent when the option is cleared again. Argument is a pointer to an inte- ger. Argument is an pointer to an integer for the test result. When a network error occurs, TCP tries to resend the packet.
Some applications require a quicker error notification.
When this option is enabled, all incoming errors are immediately passed to the user program. Use this option with care - it makes TCP less tolerant to routing changes and other normal network conditions. Linux uses the BSD compatible interpretation of the urgent pointer field by default. This violates RFC1122, but is required for interoperability with other stacks. The other end closed the socket unexpectedly or a read is executed on a shut down socket.