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
Devctl and Ioctl Commands
DCMD_FSYS_*
DCMD_FSYS_VERSION
Get version information from a filesystem

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
    - BIOC*
    - CAN_DEVCTL_*
    - DCMD_ALL_*
    - DCMD_BLK_*
    - DCMD_CAM_*
    - DCMD_CHR_*
    - DCMD_DUMPER_*
    - DCMD_F3S_*
    - DCMD_FSYS_*
      - DCMD_FSYS_CRYPTO
        Control filesystem encryption
      - DCMD_FSYS_DIRECT_IO
        Perform direct I/O
      - DCMD_FSYS_ERRNOTIFY
        Register for error notifications from a filesystem
      - DCMD_FSYS_FILE_FLAGS
        Get the flags for a file
      - DCMD_FSYS_FILTER_DETACH
        Detach the topmost filter from a filesystem
      - DCMD_FSYS_FSEVMGR_CHECK
        Notification that a filesystem event manager has been loaded
      - DCMD_FSYS_FSNOTIFY
        Notify the filesystem event policy manager
      - DCMD_FSYS_FSNOTIFY_SAVE
        Save the notification state for the filesystem event policy manager
      - DCMD_FSYS_LABEL, DCMD_FSYS_LABEL_RAW
        Get the filesystem label
      - DCMD_FSYS_MAP_OFFSET
        Map a logical filesystem offset to a physical filesystem or device offset
      - DCMD_FSYS_MOUNTED_AT, DCMD_FSYS_MOUNTED_BY, DCMD_FSYS_MOUNTED_ON
        Get mount information
      - DCMD_FSYS_OPTIONS
        Get the options that a filesystem was mounted with
      - DCMD_FSYS_PGCACHE_CTL
        Control the contents of the disk cache in io-blk.so
      - DCMD_FSYS_PREGROW_FILE
        Extend a file, optionally zero-filling it
      - DCMD_FSYS_STATISTICS, DCMD_FSYS_STATISTICS_CLR
        Get filesystem statistics
      - DCMD_FSYS_STATVFS
        Get filesystem information
      - DCMD_FSYS_VERSION
        Get version information from a filesystem
    - DCMD_IP_*
    - DCMD_MEMMGR_*
    - DCMD_MISC_*
    - DCMD_MMCSD_*
    - DCMD_PROC_*
    - DCMD_PROF_*
    - DCMD_PTPD_*
    - DCMD_SDIO_*
    - DCMD_SDMMC_*
    - DCMD_SPI_*
    - PTP_*
    - FIO*
    - TC*
    - TIOC*
  - 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.
  - SPI Framework Technote
  - QNX Cryptography Library
    The QNX Cryptography Library (qcrypto) is a flexible cryptography framework that allows you to choose which cryptography provider responds to requests on a per-process basis.
  - QNX devcrypto Service
  - 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.

DCMD_FSYS_VERSION

QNX SDP8.0Devctl and Ioctl CommandsDeveloper

Get version information from a filesystem

Synopsis:

#include <sys/dcmd_blk.h>

#define DCMD_FSYS_VERSION      __DIOTF(_DCMD_FSYS, 39, uint64_t)

Arguments to devctl():


Argument	Value
`filedes`	A file descriptor that you obtained by opening the device.
`dcmd`	DCMD_FSYS_VERSION
`dev_data_ptr`	A pointer to a uint64_t that represents the version.
`n_bytes`	`sizeof(uint64_t)`
`dev_info_ptr`	A pointer to a 32-bit signed integer. On success, the devctl() call populates this buffer with the number of bytes successfully transferred. Pass NULL if you do not want this information.

Description:

The DCMD_FSYS_VERSION command allows you to query a filesystem for version information.

To query for version information, set the uint64_t pointed to by dev_info_ptr to one of the following values:


Value	Description
FSYS_VERSION_ROLLBACK	The anti-rollback version for a QNX Trusted Disk (QTD) filesystem.

See also:

devctl() in the QNX OS C Library Reference

Page updated: August 11, 2025