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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.
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Structure that describes calendar time

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.
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- 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.
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  - C Library Reference
    - What's in a Function Description?
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      - tan(), tanf(), tanl()
        Calculate the tangent of an angle
      - tanh(), tanhf(), tanhl()
        Calculate the hyperbolic tangent
      - tcdrain()
        Wait until all output has been transmitted to a device
      - tcdropline()
        Disconnect a communications line
      - tcflow()
        Perform a flow-control operation on a data stream
      - tcflush()
        Flush the input and/or output stream
      - tcgetattr()
        Get the current terminal control settings
      - tcgetpgrp()
        Get the process group ID associated with a device
      - tcgetsid()
        Get the process group ID of the session leader for a controlling terminal
      - tcgetsize()
        Get the size of a character device
      - tcinject()
        Inject characters into a device's input buffer
      - tcischars()
        Determine the number of characters waiting to be read
      - tcsendbreak()
        Assert a break condition over a communications line
      - tcsetattr()
        Change the terminal control settings for a device
      - tcsetpgrp()
        Set the process group ID for a device
      - tcsetsid()
        Make a terminal device a controlling device
      - tcsetsize()
        Set the size of a character device
      - telldir()
        Get the location associated with the directory stream
      - tempnam()
        Create a name for a temporary file
      - termios
        Terminal control structure
      - tgamma(), tgammaf(), tgammal()
        Compute the gamma function of a number
      - thrd_create()
        Create a thread
      - thrd_current()
        Get the calling thread's ID
      - thrd_detach()
        Detach a thread from a process
      - thrd_equal()
        Compare two thread IDs
      - thrd_exit()
        Terminate a thread
      - thrd_join()
        Join thread
      - thrd_sleep()
        Make a thread sleep
      - thrd_yield()
        Yield to other ready threads at the same priority
      - thread_pool_control()
        Control the thread pool behavior
      - thread_pool_create()
        Create a thread pool handle
      - thread_pool_destroy()
        Free the memory allocated to a thread pool
      - thread_pool_limits()
        Convenience wrapper function for thread_pool_control()
      - thread_pool_start()
        Start a thread pool
      - ThreadCancel(), ThreadCancel_r()
        Cancel a thread
      - ThreadCreate(), ThreadCreate_r()
        Create a thread
      - ThreadCtl(), ThreadCtl_r(), ThreadCtlExt(), ThreadCtlExt_r()
        Control a thread
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        Destroy a thread immediately
      - ThreadDetach(), ThreadDetach_r()
        Detach a thread from a process
      - ThreadJoin(), ThreadJoin_r()
        Block until a thread terminates
      - time()
        Determine the current calendar time
      - timer_create()
        Create a timer
      - timer_delete()
        Delete a timer
      - timer_getexpstatus()
        Get the expiry status of a timer
      - timer_getoverrun()
        Return the number of timer overruns
      - timer_gettime()
        Get the amount of time left on a timer
      - timer_settime()
        Arm a timer with the given expiration time, disarm it, or set its tolerance
      - timer_timeout(), timer_timeout_r()
        Set a timeout on a blocking state
      - TimerAlarm(), TimerAlarm_r()
        Schedule a SIGALRM for delivery
      - TimerCreate(), TimerCreate_r()
        Create a timer for a process
      - TimerDelegate(), TimerDelegate_r()
        Delegate timers between CPUs
      - TimerDestroy(), TimerDestroy_r()
        Destroy a process timer
      - TimerInfo(), TimerInfo_r()
        Get information about a timer
      - TimerSettime(), TimerSettime_r()
        Arm a timer with the given expiration time, disarm it, or set its tolerance
      - TimerTimeout(), TimerTimeout_r()
        Set a timeout on a blocking state
      - times()
        Get time-accounting information
      - timespec
        Time-specification structure
      - timespec_get()
        Get the number of seconds and nanoseconds since a given epoch
      - timespec2nsec()
        Convert a timespec structure to nanoseconds
      - timezone
        The number of seconds by which the local time zone is earlier than UTC
      - tm
        Structure that describes calendar time
      - tmpfile(), tmpfile64()
        Create a temporary file
      - tmpnam()
        Generate a unique string for use as a filename
      - tolower()
        Convert a character to lowercase
      - toupper()
        Convert a character to uppercase
      - towctrans()
        Convert a wide character in a specified manner
      - towlower()
        Convert a wide character to lowercase
      - towupper()
        Convert a wide character to uppercase
      - trace_func_enter()
        Insert a trace event for the entry to a function
      - trace_func_exit()
        Insert a trace event for the exit from a function
      - _TRACE_GET_STRUCT()
        Get the flag from the header of a trace event
      - trace_here()
        Insert a trace event for the current address
      - trace_logb()
        Insert a user combine trace event
      - trace_logbc()
        Insert a trace event of an arbitrary class and type with arbitrary data
      - trace_logf()
        Insert a user string trace event
      - trace_logi()
        Insert a user simple trace event
      - trace_nlogf()
        Insert a user string trace event, specifying a maximum string length
      - trace_vnlogf()
        Insert a user string trace event, using a variable argument list
      - TraceEvent()
        Control the tracing of kernel events
      - traceparser()
        Process trace data
      - traceparser_cs()
        Attach a callback to a trace event
      - traceparser_cs_range()
        Attach a callback to a range of events
      - traceparser_debug()
        Set the traceparser debug modes
      - traceparser_destroy()
        Destroy a traceparser state structure
      - traceparser_get_info()
        Get information about traceparser
      - traceparser_init()
        Initialize the traceparser state information
      - trunc(), truncf(), truncl()
        Round to a truncated integer value
      - truncate(), truncate64()
        Truncate a file to a specified length
      - tss_create()
        Create a thread-specific storage key
      - tss_delete()
        Delete thread-specific storage
      - tss_get()
        Get a thread-specific data value
      - tss_set()
        Set a thread-specific data value
      - ttyname()
        Get a fully qualified pathname for a file
      - ttyname_r()
        Get a fully qualified pathname for a file
      - tzname
        The abbreviations for the time zone for standard and daylight savings time
      - tzset()
        Set the time according to the current time zone
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    - Glossary
  - 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.
  - 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.

tm

QNX SDP8.0C Library ReferenceAPIDeveloper

Structure that describes calendar time

Synopsis:

#include <time.h>
struct  tm {
        int tm_sec;
        int tm_min;
        int tm_hour;
        int tm_mday;
        int tm_mon;
        int tm_year;
        int tm_wday;
        int tm_yday;
        int tm_isdst;
        long int tm_gmtoff;
        const char * tm_zone;
};

Description:

The tm structure describes the calendar time. The members of this structure include:

tm_sec: Seconds after the minute, in the range [0,61], allowing for leap seconds.
tm_min: Minutes after the hour, in the range [0,59].
tm_hour: Hours after midnight, in the range [0,23].
tm_mday: Day of the month, in the range [1,31].
tm_mon: Months since January, in the range [0,11].
tm_year: Years since 1900.
tm_wday: Days since Sunday, in the range [0,6].
tm_yday: Days since January 1, in the range [0,365], allowing for leap years.
tm_isdst: Daylight saving time flag. This field is positive if daylight saving time is in effect, 0 if daylight saving time isn't in effect, and negative if the information isn't available.
tm_gmtoff: (QNX OS extension) The offset from UTC; see setlocale().
tm_zone: (QNX OS extension) A pointer to the time zone's name.
Note:
This pointer could become stale or invalid after the next call to tzset().

Classification:

ANSI, POSIX 1003.1

Page updated: August 11, 2025