Inside Macintosh: Open Transport /

Chapter 2 - Providers / Providers Reference

Functions / Sending Module-Specific Commands

OTIoctl

Sends a module-specific command to an Open Transport protocol module.

C INTERFACE

SInt32 OTIoctl(ProviderRef ref, UInt32 cmd, void* data);

C++ INTERFACE

SInt32 TProvider::Ioctl(UInt32 cmd, void* data);

PARAMETERS

ref

The provider reference of the provider affected by the specified command.

cmd

A routine selector for the module-specific command.

data

Data to be used by the module-specific command, or a pointer to such data. The interpretation of the data parameter is command specific.

DESCRIPTION

The OTIoctl function sends a module-specific command to an Open Transport protocol module. The OTIoctl function runs synchronously or asynchronously, matching the provider's mode of execution.

If the OTIoctl function completes synchronously without error, it returns 0 or a positive integer. The positive integer's meaning is command specific. If the OTIoctl function fails while executing synchronously, its return value is a negative integer corresponding to an Open Transport result code.

If the OTIoctl function runs asynchronously, it returns immediately with a return value kOTNoError or another Open Transport result code. When the function completes execution, Open Transport calls the notifier function you specify, passing the event code kStreamIoctlEvent and a result parameter indicating the result of the completed OTIoctl function. If the value of the result parameter is greater than 0, the corresponding result code is defined by the command; otherwise, the value of the result parameter corresponds to an Open Transport result code.

SPECIAL CONSIDERATIONS

Using the OTIoctl function makes your application module dependent; you should not use the OTIoctl function if you want your application to be transport independent.

SEE ALSO

Positive return values for the OTIoctl function are defined by the Open Transport module that you are using. Refer to the documentation for that module for information.