gettimeofday()_小百科

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
    - What's in a Function Description?
    - Manifests
    - Character Sets
    - A
    - B
    - C
    - D
    - E
    - F
    - G
      - getc()
        
        Get the next character from a file
      - getc_unlocked()
        
        Get the next character from a file
      - getchar()
        
        Get a character from stdin
      - getchar_unlocked()
        
        Get a character from stdin
      - getcwd()
        
        Get the name of the current working directory
      - getdelim() , getline()
        
        Read a delimited record from a stream
      - getdtablesize()
        
        Get the size of the file descriptor table
      - getegid()
        
        Get the effective group ID
      - getenv()
        
        Get the value of an environment variable
      - geteuid()
        
        Get the effective user ID
      - getfsent()
        
        Get the next entry from the filesystem table ( /etc/fstab ) file
      - getfsfile()
        
        Search for a filesystem name in the filesystem table ( /etc/fstab ) file
      - getfsspec()
        
        Search for a block special device in the filesystem table ( /etc/fstab ) file
      - getgid()
        
        Get the group ID
      - getgrent()
        
        Return an entry from the group database
      - getgrgid()
        
        Get information about the group with a given ID
      - getgrgid_r()
        
        Get information about the group with a given ID
      - getgrnam()
        
        Get information about the group with a given name
      - getgrnam_r()
        
        Get information about the group with a given name
      - getgrouplist()
        
        Determine the group access list for a user
      - getgroups()
        
        Get the supplementary group IDs of the calling process
      - gethostname()
        
        Get the name of the current host
      - GETIOVBASE() , GETIOVBASE_CONST()
        
        Get the base member of an iov_t structure
      - GETIOVLEN()
        
        Get the length member of an iov_t structure
      - getitimer()
        
        Get the value of an interval timer
      - getlogin()
        
        Get the user name associated with the calling process
      - getlogin_r()
        
        Get the user name associated with the calling process
      - getopt()
        
        Parse options from a command line
      - getopt_long() , getopt_long_only()
        
        Get long and short options from a command-line argument list
      - getpagesize()
        
        Get the memory page size (Legacy Unix)
      - getpagesizes() , getpagesizes64()
        
        Get the available page sizes
      - getpass()
        
        Prompt for and read a password
      - getpgid()
        
        Get a process group ID
      - getpgrp()
        
        Get the process group
      - getpid()
        
        Get the process ID
      - getpid64()
        
        Get the 64-bit process ID associated with a process
      - getppid()
        
        Get the parent process ID
      - getprogname()
        
        Get the name of the current program
      - getpwent()
        
        Get the next entry from the password database
      - getpwent_r()
        
        Get the next entry from the password database
      - getpwnam()
        
        Get information about the user with a given name
      - getpwnam_r()
        
        Get information about the user with a given name
      - getpwuid()
        
        Get information about the user with a given ID
      - getpwuid_r()
        
        Get information about the user with a given ID
      - getrlimit() , getrlimit64()
        
        Get the limit on a system resource
      - getrusage()
        
        Get information about resource utilization
      - gets()
        
        Get a string of characters from standard input
      - getsid()
        
        Get the session ID of a process
      - getspent() , getspent_r()
        
        Get an entry from the shadow password database
      - getspnam() , getspnam_r()
        
        Get information about a user with a given name
      - getsubopt()
        
        Parse suboptions from a string
      - gettid()
        
        Get the thread ID
      - gettimeofday()
        
        Get the current time
      - getuid()
        
        Get the user ID
      - getutent()
        
        Read the next entry from the user-information file
      - getutid()
        
        Search for an entry in the user-information file
      - getutline()
        
        Get an entry from the user-information file
      - getw()
        
        Get a word from a stream
      - getwc()
        
        Read a wide character from a stream
      - getwchar()
        
        Read a wide character from standard input
      - getwd()
        
        Get current working directory pathname
      - glob()
        
        Find paths matching a pattern
      - globfree()
        
        Free storage allocated by a call to glob()
      - gmtime()
        
        Convert calendar time to a broken-down time
      - gmtime_r()
        
        Convert calendar time to a broken-down time
      - grantpt()
        
        Grant access to a slave pseudo-terminal device
    - H
    - I
    - J
    - K
    - L
    - M
    - N
    - O
    - P
    - Q
    - R
    - S
    - T
    - U
    - V
    - W
    - X
    - Y
    - Z
    - Full Safety Information
    - 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.

A pointer to a timeval structure where the function can store the time. The struct timeval contains the following members:

time_t tv_sec — the number of seconds since the start of the Unix Epoch.

suseconds_t tv_usec — the number of microseconds. The gettimeofday() function returns the current time in when in seconds and microseconds, since the Unix Epoch, 00:00:00 January 1, 1970 Coordinated Universal Time (UTC) (formerly known as Greenwich Mean Time (GMT)). The gettimeofday() function is provided for porting existing code. You shouldn't use it in new code; use clock_gettime() instead.