Home
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
JSON Library Reference
JSON Decoding and Encoding API
JSON encoder functionality
json_encoder_length()
Get the current data length in the JSON encoder

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
    - 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 encoder functionality
        json_encoder_t
        JSON encoder structure
        json_encoder_access_buffer()
        Get a read/write pointer to the JSON encoder's data buffer
        json_encoder_add_bool()
        Add a boolean value to the JSON encoder
        json_encoder_add_double()
        Add a double value to the JSON encoder
        json_encoder_add_from_decoder()
        Add items from a JSON decoder to the JSON encoder
        json_encoder_add_int()
        Add an integer value to the JSON encoder
        json_encoder_add_int_ll()
        Add a long long integer value to the JSON encoder
        json_encoder_add_json()
        Add a JSON-encoded string value to the JSON encoder
        json_encoder_add_null()
        Add a null value to the JSON encoder
        json_encoder_add_property_name()
        Create a property in the JSON encoder
        json_encoder_add_string()
        Add a string value to the JSON encoder
        json_encoder_add_whitespace()
        Add whitespace to the JSON encoder before the next name, value, or {, }, [, or ] character
        json_encoder_buffer()
        Get a read-only pointer to the JSON encoder's data buffer
        json_encoder_cleanup()
        Clean up a JSON encoder instance, freeing any associated memory
        json_encoder_clear_option()
        Clear a JSON encoder option
        json_encoder_create()
        Create a new JSON encoder instance
        json_encoder_destroy()
        Destroy a JSON encoder instance
        json_encoder_end_array()
        End the current array in the JSON encoder
        json_encoder_end_object()
        End the current object in the JSON encoder
        json_encoder_error_t
        JSON encoder error codes
        json_encoder_format_t
        JSON encoder data format codes
        json_encoder_get_state()
        Get the current state of the JSON encoder
        json_encoder_get_status()
        Get the error status of the JSON encoder
        json_encoder_length()
        Get the current data length in the JSON encoder
        json_encoder_nesting_level()
        Get the current nesting level in the JSON encoder
        json_encoder_option_t
        Options for controlling JSON encoding behavior
        json_encoder_reserve_space()
        Reserve space for a given number of bytes in the JSON encoder's buffer
        json_encoder_reset()
        Reset a JSON encoder instance
        json_encoder_set_format()
        Set the JSON encoder format
        json_encoder_set_option()
        Set a JSON encoder option
        json_encoder_set_state()
        Set the state of the JSON encoder
        json_encoder_set_status()
        Set the error status of the JSON encoder
        json_encoder_start_array()
        Start a new array in the JSON encoder
        json_encoder_start_object()
        Start a new object in the JSON encoder
        json_encoder_state_t
        JSON encoder state
      - JSON utility functions
  - 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.
  - 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.

json_encoder_length()

QNX SDP8.0JSON Library ReferenceAPIDeveloper

Get the current data length in the JSON encoder

Synopsis:

#include <sys/json.h>

int json_encoder_length(const json_encoder_t *encoder)

Arguments:

encoder: The JSON encoder instance.

Library:

libjson

Description:

This function returns the current length of the data encoded by the given JSON encoder.

Note:

This call is not applicable to encoder instances obtained from json_decoder_get_encoder(), since JSON items encoded with these encoders are added directly to the decoder tree rather than into a JSON-formatted buffer.

Returns:

The current length of the encoded data, or -1 if the encoder instance was obtained from json_decoder_get_encoder().

Page updated: March 05, 2025