The header is a string sent by the server before transmitting HTML data to the browser using the HTTP protocol. A blank line is required between the header and the HTML file. In this article, we will share with you a summary of the different usages of headers in php.
1. The function of header() function is to send an original HTTP header [Http Header] to the client.
header(string,replace,http_response_code) /*string:必需。规定要发送的报头字符串。 replace:可选。指示该报头是否替换之前的报头,或添加第二个报头。 默认是 true(替换)。false(允许相同类型的多个报头)。 http_response_code:可选。把 HTTP 响应代码强制为指定的值。*/
Note: The header() function must be called before any actual output is sent.
2. Usage 1: Jump to the page
header("Location:https://baidu.com"); //正常跳转 header('Refresh: 3; url=https://www.baidu.com'); //3s后跳转 //在header作跳转时,避免发生错误后,代码继续执行,一般加个exit;
Usage 2: Declare content-type (I often use it to solve garbled characters)
header('content-type:text/html;charset=utf-8');
Usage 3: Return response status Code
header('HTTP/1.1 403 Forbidden')
Usage 4: Perform download operation (hide file location)
header('Content-Type: application/octet-stream'); //设置内容类型 header('Content-Disposition: attachment; filename="example.zip"');//设置MIME用户作为附件 header('Content-Transfer-Encoding: binary'); //设置传输方式 header('Content-Length: '.filesize('example.zip')); //设置内容长度
Usage 5: Control browser cache
header( 'Expires: Mon, 26 Jul 1997 05:00:00 GMT' ); //如果服务器上的网页经常变化,就把它设置为-1,表示立即过期 header( 'Last-Modified: ' . gmdate( 'D, d M Y H:i:s' ) . ' GMT' ); header( 'Cache-Control: no-store, no-cache, must-revalidate' ); header( 'Cache-Control: post-check=0, pre-check=0', false ); header( 'Pragma: no-cache' );
Usage 6:
3. More examples
<?php // ok header('HTTP/1.1 200 OK'); //设置一个404头: header('HTTP/1.1 404 Not Found'); //设置地址被永久的重定向 header('HTTP/1.1 301 Moved Permanently'); //转到一个新地址 header('Location: http://www.example.org/'); //文件延迟转向: header('Refresh: 10; url=http://www.example.org/'); print 'You will be redirected in 10 seconds'; //当然,也可以使用html语法实现 // <meta http-equiv="refresh" content="10;http://www.example.org/ /> // override X-Powered-By: PHP: header('X-Powered-By: PHP/4.4.0'); header('X-Powered-By: Brain/0.6b'); //文档语言 header('Content-language: en'); //告诉浏览器最后一次修改时间 $time = time() - 60; // or filemtime($fn), etc header('Last-Modified: '.gmdate('D, d M Y H:i:s', $time).' GMT'); //告诉浏览器文档内容没有发生改变 header('HTTP/1.1 304 Not Modified'); //设置内容长度 header('Content-Length: 1234'); //设置为一个下载类型 header('Content-Type: application/octet-stream'); header('Content-Disposition: attachment; filename="example.zip"'); header('Content-Transfer-Encoding: binary'); // load the file to send: readfile('example.zip'); // 对当前文档禁用缓存 header('Cache-Control: no-cache, no-store, max-age=0, must-revalidate'); header('Expires: Mon, 26 Jul 1997 05:00:00 GMT'); // Date in the past header('Pragma: no-cache'); //设置内容类型: header('Content-Type: text/html; charset=iso-8859-1'); header('Content-Type: text/html; charset=utf-8'); header('Content-Type: text/plain'); //纯文本格式 header('Content-Type: image/jpeg'); //JPG图片 header('Content-Type: application/zip'); // ZIP文件 header('Content-Type: application/pdf'); // PDF文件 header('Content-Type: audio/mpeg'); // 音频文件 header('Content-Type: application/x-shockwave-flash'); //Flash动画 //显示登陆对话框 header('HTTP/1.1 401 Unauthorized'); header('WWW-Authenticate: Basic realm="Top Secret"'); print 'Text that will be displayed if the user hits cancel or '; print 'enters wrong login data'; ?>
The above content is a summary of the different usages of the header function in PHP. I hope it can help everyone.
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