Manual section D7str

Intro - Introduction to STREAMS message types
M_BREAK - request that BREAK be transmitted on media
M_COPYIN - request a copyin operation
M_COPYOUT - request a copyout operation
M_CTL - send ordinary information to a particular module or type of module
M_CTL, M_PCCTL - send information to a particular module or type of module
M_DATA - carry ordinary data
M_DELAY - request realtime delay on output
M_ERROR - report downstream error condition
M_FLUSH - flush all message queues
M_HANGUP - report that the driver can no longer send data upstream
M_HANGUP, M_TRAIL - report that the driver can no longer send data upstream
M_IOCACK - positive acknowledgement of M_IOCTL message
M_IOCACK, M_IOCNAK - signal acknowledgement of M_IOCTL message
M_IOCDATA - response to an M_COPYIN or M_COPYOUT message
M_IOCNAK - negative acknowledgement of M_IOCTL message
M_IOCTL - statisfy STREAMS ioctl system calls
M_PASSFP - pass file pointer between Stream heads
M_PCCTL - send priority information to a particular module or type of module
M_PCPROTO - hold internal control information and associated data (priority)
M_PCRSE - reserved for internal use
M_PCSETOPTS - alter characteristics of the Stream head (priority)
M_PCSIG - post a high-priority signal to a process
M_PROTO - hold internal control information and associated data (non-priority)
M_PROTO, M_PCPROTO - hold internal control information and associated data
M_READ - send read request downstream
M_RSE - reserved for internal use
M_SETOPTS - alter characteristics of the Stream head (ordinary)
M_SETOPTS, M_PCSETOPTS - alter characteristics of the Stream head
M_SIG - post ordinary priority signal to a process
M_SIG, M_PCSIG - post a signal to a process
M_START - start device output
M_START, M_STOP, M_STARTI, M_STOPI - pause or restart device output or input
M_STARTI - start device input
M_STOP - pause device output
M_STOPI - pause device input
M_TRAIL - Marks end of data after M_HANGUP message