NIO CommKit Host Interface Installation and System Administration Manual

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Porting CommKit Applications To Release 4.x
Programmer-Level Compatibility
The ioctl interface supported in previous releases of the CommKit software
is no longer supported, because the interface:
• Is no longer needed due to architectural and implementation changes
• Is replaced by a library function or by an administrative command
• Is reserved for the internal use of the CommKit software and is not supported for
user-level applications code
• Has been dropped from this release.
The rest of this section gives a brief outline of the open, close, read, write,
and poll system calls, followed by a list of the old ioctl directives and their
current status.
open(2)
The open system call to STREAMS drivers remains similar to the open call
made to character drivers, with an expanded set of reasons—due to the
exhaustion of STREAMS resources—for which the open call may fail. You
may want to enhance your software to accommodate the new reason codes.
read(2)
The read system call behaves much differently with STREAMS drivers than
with character drivers. You can use the STREAMS read system call in one
of three modes:
• Byte stream
• Message non-discard
• Message discard
For more information, refer to the STREAMS programmer’s guide for
UNIX System V Release 4.