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QNX Software Development Platform
QNX SDP is a cross-compiling and debugging environment, including an IDE and command-line tools, for building binary images and programs for target boards running QNX Neutrino 7.1.
Utilities & Libraries
Addon Interfaces Library Reference
Predefined Interfaces
AOStreamer
Stream manager interface
Length()

QNX Momentics IDE User's Guide
This User's Guide describes version 7.1 of the Integrated Development Environment (IDE) that's part of the QNX Momentics tool suite.
QNX Software Development Platform
QNX SDP is a cross-compiling and debugging environment, including an IDE and command-line tools, for building binary images and programs for target boards running QNX Neutrino 7.1.
- Quickstart Guide
- OS Components & Operations
- Audio & Graphics API
- Multimedia
- Networking Middleware
- Programming
- Sensor Framework
- System Security Guide
  The QNX System Security Guide is intended for both system integrators who are responsible for the security of a QNX Neutrino RTOS system and developers who want to create a QNX Neutrino resource manager free from vulnerabilities.
- Utilities & Libraries
  - Addon Interfaces Library Reference
    - Addon Interfaces Library: Overview
      The Addon Interfaces (AOI) library (libaoi.so) provides a framework for developing and using addon interfaces.
    - Using Addon Resources
    - Predefined Interfaces
      - Recognized interfaces
        The library recognizes special interfaces for setting up and cleaning up DLLs, allowing DLLs to expose strings to applications, and assigning names to controls. A control is a programming representation of the interfaces implemented by an addon DLL or defined statically in the code.
      - AOConfigSettings
        Configuration settings interface
      - AODeConstructor
        Context creator/destructor interface
      - AODeInitializer
        DLL initializer and cleanup interface
      - AOExtInspector
        File extension rating interface
      - AOFormatInspector
        Data-processing rating interface
      - AOMimetypeInspector
        Mimetype rating interface
      - AOStreamer
        Stream manager interface
        Close()
        ContextOpen()
        GetError()
        Length()
        Open()
        Read()
        Seek()
        SideInfo()
        Sniff()
        Tell()
        Write()
      - AOStreamerMimeInfo
        Streamer MIME information interface
      - AOStreamInspector
        Stream rating interface
      - AOResourceAccess
        Resource accessor interface
    - Defined Structures
    - Core API Reference
  - C Library Reference
  - Devctl and Ioctl Commands
  - JSON Library Reference
  - PAM Reference
  - Utilities Reference
  - WPA Control Interface Reference
    This document provides a reference for the Wi-Fi Protected Access (WPA) control interface, which provides a C API for the WPA/IEEE 802.11i protocols in Wi-Fi client stations. Application developers who want to control WPA operations and get associated status and event data should read this reference.
QNX Hypervisor
The QNX Hypervisor allows you to run multiple OSs on a target system so you can separate critical and non-critical functions, support a wide variety of applications, and reduce hardware costs.
QNX Software in the Cloud
QNX Software in the Cloud enables developers to use the QNX software in Amazon Web Services (AWS) and Microsoft Azure (Azure).
QNX Advanced Virtualization Frameworks User's Guide
This User's Guide is aimed at all systems integrators and developers who want to design and build embedded systems using the QNX Advanced Virtualization Frameworks.
Typographical Conventions, Support, and Licensing
This section describes the typographical conventions used throughout the documentation and explains how to obtain technical support.

Length()

Synopsis:

#include <aoi.h>

int64_t (*Length)(void *ctx);

Arguments:

ctx: The context for the stream you're querying.

Description:

This function should return the length of the stream, if known.

Returns:

The length of the stream (in bytes), or -1 if the length is unknown.

Page updated: March 12, 2026