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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 the QNX OS 8.0.
Utilities & Libraries
QNX Helpers Developer's Guide
These libraries provide QNX helpers, including helpers that assist with logging, string conversion, and number and type sizes.
error.h
QNX helpers - Helpers related to the errno variable.
Macros
These macros are related to errno handling.
QH_SET_ERRNO()
A macro that sets errno

QNX Momentics IDE User's Guide
This User's Guide describes version 8.0 of the Integrated Development Environment (IDE) that's part of the QNX 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 the QNX OS 8.0.
- Quickstart Guide
- System Architecture
  The System Architecture guide accompanies the QNX OS and is intended for both application developers and end-users.
- OS Components & Operations
- Graphics
- Programming
- System Security Guide
  The QNX System Security Guide is intended for both system integrators who are responsible for the security of a QNX OS system and developers who want to create a QNX OS resource manager free from vulnerabilities.
- Utilities & Libraries
  - C Library Reference
  - Devctl and Ioctl Commands
  - JSON Library Reference
  - PAM Reference
  - QNX Helpers Developer's Guide
    These libraries provide QNX helpers, including helpers that assist with logging, string conversion, and number and type sizes.
    - attr.h
      QNX helpers - Attribute helpers.
    - endian.h
      QNX helpers - Endianness-related helpers.
    - error.h
      QNX helpers - Helpers related to the errno variable.
      - Macros
        These macros are related to errno handling.
        QH_ABORT()
        Convenience macro that logs an error message using a QNX helpers function and then calls abort()
        QH_ABORT_ON_ERRNO()
        A convenience macro that allows you to call qh_abort_on_errno() without specifying qh_log_info
        QH_RET_ERRNO()
        A macro that sets errno and returns its value
        QH_SET_ERRNO()
        A macro that sets errno
        QH_RET_ERRNO_WEOK()
        A macro that conditionally sets errno and always returns the specified error
        QH_RET_ON_ERRNO()
        A macro that conditionally (if not EOK) sets errno and returns the specified error
      - qh_abort_on_errno()
        Conditionally log an error message using QNX helpers logging functions and then call abort() if the specified errno is not EOK
      - qh_set_errno()
        Set errno
      - qh_set_errno_on_error()
        Conditionally set errno
      - qh_sticky_error()
        Store a new error code as a variable if the new error is not zero and the previously stored one is
      - qh_sticky_error_last()
        Store a new error code as a variable if the new error is not zero
      - qh_strerror()
        Convert an error number into an error message and guarantee that errno is kept intact in the process
    - io.h
      QNX helpers - IO helpers.
    - log.h
      QNX helpers related to logging.
    - misc.h
      QNX helpers - Miscellaneous helpers.
    - qh.h
      QNX helpers that set QH_FILENAME.
    - size.h
      QNX helpers - Size-related helpers.
    - string.h
      QNX helpers - Helpers related to strings and string conversions.
    - time.h
      QNX helpers - Helpers related to time.
  - SPI Framework Technote
  - 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.
- Migrating to QNX OS 8.0
QNX Software in the Cloud
QNX Software in the Cloud enables developers to use the QNX OS in the Amazon cloud environment.
QNX Toolkit for Visual Studio Code
This User's Guide describes the QNX^® Toolkit for Visual Studio Code. The guide introduces you to the QNX Toolkit by explaining the QNX development environment and how to build, run, and debug your QNX^® Operating System (OS) applications and systems.
QNX Hypervisor User's Guide
This User's Guide explains the QNX hypervisor architecture and provides instructions for installing and running a QNX Hypervisor system, changing system components and configuration, and using hypervisor features such as virtual devices (vdevs).
Typographical Conventions, Support, and Licensing
This section describes the typographical conventions used throughout the documentation, explains how to obtain technical support, and provides some information about licensing.

QH_SET_ERRNO()

QNX SDP8.0QNX Helpers Developer's GuideAPIDeveloper

A macro that sets errno

Synopsis:

#include <qh/error.h>

#define QH_SET_ERRNO(errval)

Arguments:

errval: The standard errno to set errno to.

Library:

Description:

Because what is passed in to the macro is only evaluated once, it is safe to execute operations as part of calling the macro.

Page updated: March 05, 2025