search
HomeBackend DevelopmentPHP TutorialImplement timer function using PHP

In the past, I only knew that JS could be used to implement the timer function, and it was very convenient. However, during the project today, I needed to implement a functional module. When I was doing a certain part of it, I thought it would be great if I could implement the timer function through PHP. So I searched online and found that similar functions can be achieved by using the ignore_user_abort() function together with the set_time_limit() function and an infinite loop. Although the project did not use this function in the end, I felt that the potential use value was still very high, so I later referred to some information on the Internet and compiled it as follows:

<?php // 1、范例代码:
    ignore_user_abort(true);  // 设置与客户机断开是否会终止脚本的执行。
    set_time_limit(0);        // 设置脚本超时时间,为0时不受时间限制
    ob_end_clean();           // 清空缓存
    ob_start();               // 开始缓冲数据
    while(1){
        echo str_repeat(" ",1024);  // 写满IE有默认的1k buffer
        ob_flush();                 // 将缓存中的数据压入队列
        flush();                    // 输出缓存队列中的数据
        echo "now time is ".date(&#39;h:i:s&#39;);  // 打印数据,其实是先将数据存入了缓存中
        usleep(1000000);            //延迟一秒(暂停一秒)
    }
    // 该段程序实现的功能是每隔一秒钟输出一次包含当前时间的字符串。

    // 2、说明:
    // 经过测试,范例结果中会出现不连续输出,如果要求实现连续、均匀的输出效果(如输出时间),则应设置缓存;为方便理解,提供相关函数作用说明如下:
    /*
    ①ignore_user_abort(bool):设置与客户机断开是否会终止脚本的执行。
    ②set_time_limit(int seconds)设置允许脚本运行的时间,单位为秒。参数值为0时不受限制。
    ③ob_end_clean():清除服务端缓存的数据
    ④ob_start():开启一个缓存(可嵌套)
    ⑤ob_flush():将缓存中的数据压入队列
    ⑥flush():输出缓存队列中的数据
    ⑦usleep(int m-seconds):以指定的微秒数延缓程序的执行。
    */
    // 注:
    // flush()和ob_flush()的正确顺序应是,先ob_flush()再flush(),不可弄混。
    // usleep()函数可替换成sleep()函数,不同之处在于sleep()的参数是秒。

The above has introduced the use of PHP to implement the timer function, including various aspects. I hope it will be helpful to friends who are interested in PHP tutorials.

Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
How can you check if a PHP session has already started?How can you check if a PHP session has already started?Apr 30, 2025 am 12:20 AM

In PHP, you can use session_status() or session_id() to check whether the session has started. 1) Use the session_status() function. If PHP_SESSION_ACTIVE is returned, the session has been started. 2) Use the session_id() function, if a non-empty string is returned, the session has been started. Both methods can effectively check the session state, and choosing which method to use depends on the PHP version and personal preferences.

Describe a scenario where using sessions is essential in a web application.Describe a scenario where using sessions is essential in a web application.Apr 30, 2025 am 12:16 AM

Sessionsarevitalinwebapplications,especiallyfore-commerceplatforms.Theymaintainuserdataacrossrequests,crucialforshoppingcarts,authentication,andpersonalization.InFlask,sessionscanbeimplementedusingsimplecodetomanageuserloginsanddatapersistence.

How can you manage concurrent session access in PHP?How can you manage concurrent session access in PHP?Apr 30, 2025 am 12:11 AM

Managing concurrent session access in PHP can be done by the following methods: 1. Use the database to store session data, 2. Use Redis or Memcached, 3. Implement a session locking strategy. These methods help ensure data consistency and improve concurrency performance.

What are the limitations of using PHP sessions?What are the limitations of using PHP sessions?Apr 30, 2025 am 12:04 AM

PHPsessionshaveseverallimitations:1)Storageconstraintscanleadtoperformanceissues;2)Securityvulnerabilitieslikesessionfixationattacksexist;3)Scalabilityischallengingduetoserver-specificstorage;4)Sessionexpirationmanagementcanbeproblematic;5)Datapersis

Explain how load balancing affects session management and how to address it.Explain how load balancing affects session management and how to address it.Apr 29, 2025 am 12:42 AM

Load balancing affects session management, but can be resolved with session replication, session stickiness, and centralized session storage. 1. Session Replication Copy session data between servers. 2. Session stickiness directs user requests to the same server. 3. Centralized session storage uses independent servers such as Redis to store session data to ensure data sharing.

Explain the concept of session locking.Explain the concept of session locking.Apr 29, 2025 am 12:39 AM

Sessionlockingisatechniqueusedtoensureauser'ssessionremainsexclusivetooneuseratatime.Itiscrucialforpreventingdatacorruptionandsecuritybreachesinmulti-userapplications.Sessionlockingisimplementedusingserver-sidelockingmechanisms,suchasReentrantLockinJ

Are there any alternatives to PHP sessions?Are there any alternatives to PHP sessions?Apr 29, 2025 am 12:36 AM

Alternatives to PHP sessions include Cookies, Token-based Authentication, Database-based Sessions, and Redis/Memcached. 1.Cookies manage sessions by storing data on the client, which is simple but low in security. 2.Token-based Authentication uses tokens to verify users, which is highly secure but requires additional logic. 3.Database-basedSessions stores data in the database, which has good scalability but may affect performance. 4. Redis/Memcached uses distributed cache to improve performance and scalability, but requires additional matching

Define the term 'session hijacking' in the context of PHP.Define the term 'session hijacking' in the context of PHP.Apr 29, 2025 am 12:33 AM

Sessionhijacking refers to an attacker impersonating a user by obtaining the user's sessionID. Prevention methods include: 1) encrypting communication using HTTPS; 2) verifying the source of the sessionID; 3) using a secure sessionID generation algorithm; 4) regularly updating the sessionID.

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

SAP NetWeaver Server Adapter for Eclipse

SAP NetWeaver Server Adapter for Eclipse

Integrate Eclipse with SAP NetWeaver application server.

Atom editor mac version download

Atom editor mac version download

The most popular open source editor

SecLists

SecLists

SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

EditPlus Chinese cracked version

EditPlus Chinese cracked version

Small size, syntax highlighting, does not support code prompt function