SVR5 and SCO OpenServer 5

M_PASSFP(D7str)

M_PASSFP -- pass file pointer between Stream heads

Description

This message type is used by STREAMS to pass a file pointer from the Stream head at one end of a Stream pipe to the Stream head at the other end of the same Stream pipe. (A Stream pipe is a Stream that is terminated at both ends by a Stream head; one end of the Stream can always find the other by following the q_next pointers in the Stream. The means by which such a structure is created are not described in this document.)

The message is generated as a result of an I_SENDFD ioctl issued by a process to the sending Stream head.

The only devices that allow this message to be passed are loopback-style STREAMS devices where both ends of the Stream are Stream heads. In other words, both ends are user-level programs rather than devices. These include spx, the STREAMS pipe driver, ticots, ticlts, and ticotsord.

Note that a pipe system call returns a pipe that consists of a Stream, but it does not allow this message.

Message type

Ordinary (non-priority).

Version applicability

ddi: 1, 2, 3, 4, 5, 5mp, 6, 6mp, 7, 7mp, 7.1, 7.1mp, 8, 8mp
oddi: 1, 2, 2mp, 3, 3mp, 4, 4mp, 5, 5mp

References

spx, streamio