Technical Reference: Communications, Volume 2

putpmsg System Call

Purpose

Sends a priority message on a stream.

Syntax

#include <stropts.h>

int putpmsg (fd, ctlptr, dataptr, band, flags) int fd; struct strbuf * ctlptr; struct strbuf * dataptr; int band; int flags;

Description

The putpmsg system call is identical to the putmsg system call except that it sends a priority message. All information except for flag settings are found in the description for the putmsg system call. The differences in the flag settings are noted in the error codes section.

This system call is part of STREAMS Kernel Extensions.

Parameters

fd	Specifies a file descriptor referencing an open stream.
ctlptr	Holds the control part of the message.
dataptr	Holds the data part of the message.
band	Indicates the priority band.
flags	Indicates the priority type of message to be sent. Acceptable values are: MSG_BAND Sends a non-priority message. MSG_HIPRI Sends a priority message.

Error Codes

The putpmsg system call is unsuccessful under the following conditions:

The flags parameter is set to a value of 0.
The flags parameter is set to MSG_HIPRI and the band parameter is set to a nonzero value.
The flags parameter is set to MSG_HIPRI and no control part is specified.

Related Information

The poll subroutine, read subroutine, write subroutine.

The getmsg system call, getpmsg system call, putmsg system call.

List of Streams Programming References and STREAMS Overview in AIX 5L Version 5.2 Communications Programming Concepts.