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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.
OS Components & Operations
Persistent Publish/Subscribe Developer's Guide
Options and Qualifiers
Pathname open options
PPS objects support an extended syntax on the pathnames used to open them.
Filtering notifications
You can filter PPS notifications based on the names of attributes, the values of attributes, or a combination of the two.

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
  - Adaptive Partitioning User's Guide
  - Boot Optimization Guide
    The Boot Optimization Guide describes techniques you can use to reduce the time from your board's initial power on until you have a fully functional QNX system running on the board.
  - Building Embedded Systems
    The Building Embedded Systems guide is intended for developers who are developing or building BSPs for QNX Neutrino RTOS embedded systems.
  - Core Networking Stack User's Guide
    This guide introduces you to the QNX Neutrino Core Networking stack and its manager, io-pkt.
  - Customizing a BSP
    While QNX provides Board Support Packages (BSPs) for many common platforms and their individual variants, in some cases, you need a BSP for a board that QNX does not provide. If this is the case, you can modify a QNX BSP or develop your own.
  - Device Publishers Developer's Guide
  - High Availability Framework Developer's Guide
  - High-Performance Networking Stack (io-sock) User's Guide
    This guide contains instructions for implementing and using the QNX Neutrino High-Performance Networking Stack and its manager, io-sock.
  - Instant Device Activation
  - Migrating to QNX SDP 7.1
  - PCI Server User's Guide
  - Persistent Publish/Subscribe Developer's Guide
    - QNX Neutrino PPS Service
      The QNX Neutrino Persistent Publish/Subscribe (PPS) service is a small, extensible publish and subscribe service that offers persistence across reboots. It's designed to provide a simple and easy-to-use solution for both publish/subscribe and persistence in embedded systems, answering a need for building loosely connected systems using asynchronous publications and notifications.
    - Objects and Their Attributes
      The QNX Neutrino PPS service is a system with objects whose properties a publisher can modify.
    - Persistence
    - Publishing
    - Subscribing
      PPS clients can subscribe to multiple objects, and PPS objects can have multiple subscribers. When a publisher changes an object, all clients subscribed to that object are informed of the change.
    - Options and Qualifiers
      - Pathname open options
        PPS objects support an extended syntax on the pathnames used to open them.
        The critical option
        You can use the critical option as a mechanism to clean up attributes on the abnormal termination of a publisher.
        Filtering notifications
        You can filter PPS notifications based on the names of attributes, the values of attributes, or a combination of the two.
      - Object and attribute qualifiers
        PPS supports qualifiers to objects and their attributes.
      - Reading and writing from the command line
        You can use standard command-line utilities to view the status of objects or to change their attributes.
      - Access Control List configuration file
        The -A option for the pps command specifies the path to an Access Control List (ACL) configuration file, which can be used to set access permissions. Using the ACL configuration file eliminates reads to establish PPS object access permissions at startup, and can thus be used to reduce startup times.
    - Server Objects
    - PPS Encoding and Decoding API
      The PPS encoding and decoding API makes it easy to encode and decode complex data structures such as arrays and objects in PPS attributes and to ensure attributes are properly typed.
    - PPS API reference
      This chapter describes the publicly visible PPS API functions and data types.
    - Examples
  - Platform-independent Publish/Subscribe Developer's Guide
    This guide is intended for application developers who want to use the Platform-independent Publish Subscribe (PiPS) framework to exchange information with other applications. First, the overall PiPS design and data-exchange model are explained. Then, tutorials on using PiPS are given. These tutorials cover key tasks such as selecting a publish-subscribe provider to use and writing plugins that read and write custom data types.
  - QDB Developer's Guide
  - QNX Helpers Developer's Guide
    These libraries provide QNX helpers, including helpers that assist with logging, string conversion, and number and type sizes.
  - SMMUMAN User's Guide
  - System Analysis Toolkit (SAT) User's Guide
  - System Architecture
    The System Architecture guide accompanies the QNX Neutrino RTOS and is intended for both application developers and end-users.
  - Technotes
  - User's Guide
    The QNX Neutrino User's Guide is intended for all users of a QNX Neutrino RTOS system, from system administrators to end users.
- 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
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.

Filtering notifications

You can filter PPS notifications based on the names of attributes, the values of attributes, or a combination of the two.

To filter notifications, use the following syntax:

f=attrspec{+attrspec}...

where attrspec is an attribute specification consisting of either an attribute's name or an expression specifying an attribute's value. If you want to be notified when the attribute is deleted, add a minus sign (-) before its name:

f=-attr

The syntax for specifying an attribute's value is:

attroperatorvalue

where attr is the attribute's name, operator is the operator used to determine the threshold for triggering notifications, and value is the value to compare to.

Supported operators are:

<, <=, >, >=, =, ==, and != for integers. Integer values must be in the range of a long long; otherwise they're treated as strings.
=, ==, and != for strings. Note that = and == are synonymous. String values can include the + character, but only by escaping it with \.

If you specify only an attribute's name, PPS notifies you of any updates where an attribute with that name is set. If you specify a name, operator, and value, PPS notifies you of any updates where the named attribute is set to a value that matches the given operator and value expression.

In both full and delta modes, the file descriptor will get notifications if any of the attribute specifications match:

In full mode, the entire object is returned.
In delta mode, only the specified attributes are returned. Changes to other attributes are filtered out.

In the following examples, the name of the object being opened is "objname":

/pps/objname?delta,f=attr1+attr2 — return change notifications for only the attributes named "attr1" and "attr2"
/pps/objname?delta,f=attr1<37 — return change notifications for only the attribute named "attr1" when its value is less than 37
/pps/objname?f=attr2<0+attr2>100 — return change notifications for the entire object when the attribute "attr2" has an integer value less than 0 or greater than 100
/pps/objname?delta,f=attr1=a\+b — return change notifications only for the attribute "attr1" when it has a string value of "a+b"
/pps/objname?delta,f=attr1+attr2<10 — return change notifications only for the attribute "attr1" (for any change) and attribute "attr2" when it has an integer value less than 10.

Page updated: March 12, 2026