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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
JSON Library Reference
JSON Decoding and Encoding API
JSON decoder functionality
json_decoder_type()
Get the type of the current or specified node

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
  - C Library Reference
  - Devctl and Ioctl Commands
  - JSON Library Reference
    - JSON Library Overview
      The JSON library, libjson, allows applications to decode and encode JSON data. This is useful for reading and interpreting complex data or transferring data between systems.
    - JSON Decoding and Encoding API
      - JSON decoder functionality
        json_decoder_t
        JSON decoder structure
        json_decoder_cleanup()
        Clean up a JSON decoder instance, freeing any memory allocated for the decoder tree
        json_decoder_create()
        Create a new JSON decoder instance
        json_decoder_destroy()
        Destroy a JSON decoder instance
        json_decoder_dump_tree()
        Dump the tree contents of a JSON decoder
        json_decoder_error_t
        JSON decoder error codes
        json_decoder_free_state()
        Free a previously saved JSON decoder state
        json_decoder_get_bool()
        Get the boolean value from the current or the specified node
        json_decoder_get_data_version()
        Get the current data version for the decoder
        json_decoder_get_double()
        Get the double value from the current or the specified node
        json_decoder_get_encoder()
        Return an encoder instance for adding or updating nodes in the decoder tree
        json_decoder_get_int()
        Get the integer value from the current or the specified node
        json_decoder_get_int_ll()
        Get the long long integer value from the current or the specified node
        json_decoder_get_offset()
        Get the offset of the node's value within the original JSON string
        json_decoder_get_parse_error()
        Get the location and reason for a parse error
        json_decoder_get_state()
        Get the current state of the JSON decoder
        json_decoder_get_status()
        Get the error status of the JSON decoder
        json_decoder_get_string()
        Get the string value from the current or the specified node
        json_decoder_index()
        Get the index of the current node
        json_decoder_is_integer()
        Determine if a node represents an integer value
        json_decoder_length()
        Get the number of elements in the current node
        json_decoder_name()
        Get the name of the current property
        json_decoder_next()
        Move to the next node in the current array or object
        json_decoder_parse_error_t
        JSON decoder parser error codes
        json_decoder_parse_file()
        Parse a file of JSON data
        json_decoder_parse_json_str()
        Parse a string of JSON data
        json_decoder_pop()
        Ascend out of an object or array
        json_decoder_position_index()
        Move to the specified node in the current array or object
        json_decoder_position_property()
        Position the decoder at the specified property
        json_decoder_previous()
        Move to the previous node in the current array or object
        json_decoder_push_array()
        Descend into an array
        json_decoder_push_object()
        Descend into an object
        json_decoder_remove_node()
        Remove a node from the decoder tree
        json_decoder_reset()
        Reset a JSON decoder instance
        json_decoder_set_data_version()
        Set the data version for the decoder
        json_decoder_set_state()
        Set the state of the JSON decoder
        json_decoder_set_status()
        Set the error status of the JSON decoder
        json_decoder_state_t
        JSON decoder state
        json_decoder_type()
        Get the type of the current or specified node
        json_node_type_t
        JSON decoder node types
      - JSON encoder functionality
      - JSON utility functions
  - 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.

json_decoder_type()

Get the type of the current or specified node

Synopsis:

#include <sys/json.h>

json_node_type_t json_decoder_type(json_decoder_t *decoder,
                                   const char *name);

Arguments:

decoder: The JSON decoder instance.
name: The name of the node to provide the type for, or NULL to provide the type of the current node.

Library:

libjson

Returns:

The type of the referenced node (see json_node_type_t) or JSON_TYPE_NONE if the specified node does not exist.

Page updated: March 12, 2026