php header函数实现代码
PHP header() 函数定义和用法header() 函数向客户端发送原始的 HTTP 报头。认识到一点很重要,即必须在任何实际的输出被发送之前调用 header() 函数(在 PHP 4 以及更高的版本中,您可以使用输出缓存来解决此问题):
php教程 header() 函数
定义和用法
header() 函数向客户端发送原始的 http 报头。
认识到一点很重要,即必须在任何实际的输出被发送之前调用 header() 函数(在 php 4 以及更高的版本中,您可以使用输出缓存来解决此问题):
location
refresh
content-type
expires(意思为终止)
last-modified等。
location – 浏览器显示指定的网页。
格式: header(“location: http://绝对地址”);
location 的地址必须是一个绝对地址。
refresh
refresh – 更新网页。
// 结果出错
// 在调用 header() 之前已存在输出
header('location: http://www.bkjia.com/');
?>语法
header(string,replace,http_response_code)
该函数防止一次发送多个报头
// date in the past
header("expires: mon, 26 jul 1997 05:00:00 gmt");
header("cache-control: no-cache");
header("pragma: no-cache");
?>
提示用户保存一个生成的 pdf 文件(content-disposition 报头用于提供一个推荐的文件名,并强制浏览器显示保存对话框):
当时间超过指定时间就表示网页内容已经失效。 其格式如下
expires = “expires:” http-date
例 如: header(“expires: fri, 31 oct 2003 18:00:00 gmt”); 表示2003年10月31日星期五 18时。
header(“expires: wed, 30 jun 2004 09:00:00 gmt”); 表示2004年6月30日星期三 9时。
last-modified = “last-modified” “:” http-date
例如 header(“last-modified: wed, 01 jan 2003 12:00:00 gmt”); 上次修改时间2003年1月1日12时
cache control
no-cache 使得服务器的数据可以传送到远程的使用者, 而不会被暂存 (cache) 起来。
no-store 是预防不良的版本或者是敏感的信息被保留下来。
must-revalidate 是指必须要再评估信息, 如果暂存 (cached) 的数据是无效的则让服务器与使用者端联机
date 是说明数据内容的建立日期及时间。 其格式如下: date = “date:” http-date
范例: header(“date: sun, 15 feb 2004 08:00:00 gmt”); 建立日期是2004年2月15日8时。
header("content-type:application/pdf");// 文件将被称为 downloaded.pdf
header("content-disposition:attachment;filename='downloaded.pdf'");// pdf 源在 original.pdf 中
readfile("original.pdf");
?>

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

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

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics



PHP 8.4 brings several new features, security improvements, and performance improvements with healthy amounts of feature deprecations and removals. This guide explains how to install PHP 8.4 or upgrade to PHP 8.4 on Ubuntu, Debian, or their derivati

Visual Studio Code, also known as VS Code, is a free source code editor — or integrated development environment (IDE) — available for all major operating systems. With a large collection of extensions for many programming languages, VS Code can be c

If you are an experienced PHP developer, you might have the feeling that you’ve been there and done that already.You have developed a significant number of applications, debugged millions of lines of code, and tweaked a bunch of scripts to achieve op

This tutorial demonstrates how to efficiently process XML documents using PHP. XML (eXtensible Markup Language) is a versatile text-based markup language designed for both human readability and machine parsing. It's commonly used for data storage an

JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,

A string is a sequence of characters, including letters, numbers, and symbols. This tutorial will learn how to calculate the number of vowels in a given string in PHP using different methods. The vowels in English are a, e, i, o, u, and they can be uppercase or lowercase. What is a vowel? Vowels are alphabetic characters that represent a specific pronunciation. There are five vowels in English, including uppercase and lowercase: a, e, i, o, u Example 1 Input: String = "Tutorialspoint" Output: 6 explain The vowels in the string "Tutorialspoint" are u, o, i, a, o, i. There are 6 yuan in total

Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.

What are the magic methods of PHP? PHP's magic methods include: 1.\_\_construct, used to initialize objects; 2.\_\_destruct, used to clean up resources; 3.\_\_call, handle non-existent method calls; 4.\_\_get, implement dynamic attribute access; 5.\_\_set, implement dynamic attribute settings. These methods are automatically called in certain situations, improving code flexibility and efficiency.
