System Calls Used

Table 4-1 summarizes the system calls commonly used in controlling and transferring data and messages within a Stream.

Table 4-1 System Calls Used


manpage	Description
read(2)	Reads data from a Stream
write(2)	Writes data to a Stream
ioctl(2)	Controls a Stream
getmsg(2)	Receives a message at the Stream head
`getpmsg(2)`	Receives a priority message at the Stream head
putmsg(2)	Sends a message downstream
`putpmsg(2)`	Sends a priority message downstream
poll(2)	Identifies files on which a user can send or receive messages, or on which certain events have occurred (not restricted to streams, although historically was)
pipe(2)	Creates a bidirectional channel that provides a communication path between multiple processes