Definition and usage of PHP file_get_contents() function
定义和用法
file_get_contents() 把整个文件读入一个字符串中。
该函数是用于把文件的内容读入到一个字符串中的首选方法。如果服务器操作系统支持,还会使用内存映射技术来增强性能。
语法
file_get_contents(path,include_path,context,start,max_length)
参数描述:
path 必需。规定要读取的文件。
include_path 可选。如果您还想在 include_path(在 php.ini 中)中搜索文件的话,请设置该参数为 '1'。
context 可选。规定文件句柄的环境。context 是一套可以修改流的行为的选项。若使用 NULL,则忽略。
start 可选。规定在文件中开始读取的位置。该参数是 PHP 5.1 中新增的。
max_length 可选。规定读取的字节数。该参数是 PHP 5.1 中新增的。
提示和注释
提示:该函数是二进制安全的。(意思是二进制数据(如图像)和字符数据都可以使用此函数写入。)
实例用法展示:
file_get_contents函数轻松采集html数据:
<?php
//全国,判断条件是$REQUEST_URI是否含有html
if (!strpos($_SERVER["REQUEST_URI"],".html"))
{
$page="http://qq.ip138.com/weather/";
$html = file_get_contents($page,'r');
$pattern="/<B>全国主要城市、县当天和未来五天天气趋势预报在线查询<\/B>(.*?)<center style=\"padding\:3px\">/si";
//正则匹配之间的html
preg_match($pattern,$html,$pg);
echo "";
//正则替换远程地址为本地地址
$p=preg_replace('/\/weather\/(\w+)\/index.htm/', 'tq.php/$1.html', $pg[1]);
echo $p;
}
//省,判断条件是$REQUEST_URI是否含有?
else if(!strpos($_SERVER["REQUEST_URI"],"?")){
//yoyo推荐的使用分割获得数据,这里是获得省份名称
$province=explode("/",$_SERVER["REQUEST_URI"]);
$province=explode(".",$province[count($province)-1]);
$province=$province[0];
//被注释掉的是我自己写出来的正则,感觉写的不好,但效果等同上面
//preg_match('/[^\/]+[\.(html)]$/',$_SERVER["REQUEST_URI"],$pro);
//$province=preg_replace('/\.html/','',$pro[0]);
$page="http://qq.ip138.com/weather/".$province."/index.htm";
//获取html数据之前先尝试打开页面,防止恶意输入地址导致出错
if (!@fopen($page, "r")) {
die("对不起,该地址不存在!<a href=javascript:history.back(1)>点击这里返回</a>");
exit(0);
}
$html = file_get_contents($page,'r');
$pattern="/五天天气趋势预报<\/B>(.*?)请输入输入市/si";
preg_match($pattern,$html,$pg);
echo "";
//正则替换,获取省份,城市
$p=preg_replace('/\/weather\/(\w+)\/(\w+).htm/', '$2.html?pro=$1', $pg[1]);
echo $p;
}
else {
//市,通过get传递省份
$pro=$_REQUEST['pro'];
$city=explode("/",$_SERVER["REQUEST_URI"]);
$city=explode(".",$city[count($city)-1]);
$city=$city[0];
//preg_match('/[^\/]+[\.(html)]+[\?]/',$_SERVER["REQUEST_URI"],$cit);
//$city=preg_replace('/\.html\?/','',$cit[0]);
$page="http://qq.ip138.com/weather/".$pro."/".$city.".htm";
if (!@fopen($page, "r")) {
die("对不起,该地址不存在!<a href=javascript:history.back(1)>点击这里返回</a>");
exit(0);
}
$html = file_get_contents($page,'r');
$pattern="/五天天气趋势预报<\/B>(.*?)请输入输入市/si";
preg_match($pattern,$html,$pg);
echo "";
//获取真实的图片地址
$p=preg_replace('/\/image\//', 'http://qq.ip138.com/image/', $pg[1]);
echo $p;
}
?>The above is the detailed content of Definition and usage of PHP file_get_contents() function. For more information, please follow other related articles on the PHP Chinese website!
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
AI Hentai Generator
Generate AI Hentai for free.
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
1378
52
PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian
Dec 24, 2024 pm 04:42 PM
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
How To Set Up Visual Studio Code (VS Code) for PHP Development
Dec 20, 2024 am 11:31 AM
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
7 PHP Functions I Regret I Didn't Know Before
Nov 13, 2024 am 09:42 AM
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
How do you parse and process HTML/XML in PHP?
Feb 07, 2025 am 11:57 AM
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
Explain JSON Web Tokens (JWT) and their use case in PHP APIs.
Apr 05, 2025 am 12:04 AM
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,
PHP Program to Count Vowels in a String
Feb 07, 2025 pm 12:12 PM
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
Explain late static binding in PHP (static::).
Apr 03, 2025 am 12:04 AM
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 PHP magic methods (__construct, __destruct, __call, __get, __set, etc.) and provide use cases?
Apr 03, 2025 am 12:03 AM
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.


