Home Backend Development PHP Problem How to limit file suffix upload in php

How to limit file suffix upload in php

Sep 04, 2019 pm 03:33 PM
php

How to limit file suffix upload in php

#PHP image file upload type limit, extension limit, size limit and automatic detection of directory creation.

The code is divided into two parts:

Part form form: (Recommended learning: PHP video tutorial)

<!doctype html><br/><html><br/><head><br/><title>文件上传案例-file upload example</title><br/><meta http-equiv="content-type" contnet="text/html" charset="utf-8"/><br/></head><br/><body><br/><h1>文件上传支持图片.gif.png.jpg.jpeg限制200kb大小的文件</h1><br/><form method="POST" action="upload_file.php" enctype="multipart/form-data"><br/><lable for="file">File:</lable><br/><input name="file" type="file" id="file"/><br/><br/><input type="submit" value="上传文件"/><br/></form><br/></body><br/></html><br/>
Copy after login

two Part of the PHP background upload verification program:

<meta charset="utf-8"/><br/><?php<br/>$array=array("gif","png","jpg","jpeg");//赋值一个数组<br/>$tmp=explode(".",$_FILES[&#39;file&#39;][&#39;name&#39;]);//用explode()函数把字符串打散成为数组。<br/>$extension=end($tmp);//用end获取数组最后一个元素<br/>if($_FILES[&#39;file&#39;][&#39;error&#39;]>0){//判断提交上的文件是否为空或错误<br/>    echo "文件未选择,或非法文件!错误:".$_FILES[&#39;file&#39;][&#39;error&#39;];<br/>}else{<br/>    if((($_FILES[&#39;file&#39;][&#39;type&#39;]=="image/gif")//判断提交上的文件的文件类型是否正确和文件扩展名是否正确,文件大小是否超2048kb。<br/>    ||($_FILES[&#39;file&#39;][&#39;type&#39;]=="image/png")<br/>    ||($_FILES[&#39;file&#39;][&#39;type&#39;]=="image/jpeg")<br/>    ||($_FILES[&#39;file&#39;][&#39;type&#39;]=="image/jpg")<br/>    ||($_FILES[&#39;file&#39;][&#39;type&#39;]=="image/pjpeg")<br/>    ||($_FILES[&#39;file&#39;][&#39;type&#39;]=="image/x-png"))<br/>    &&($_FILES[&#39;file&#39;][&#39;size&#39;]<204800)<br/>    &&in_array($extension,$array)){<br/>        echo "文件大小和文件扩展名验成功!<br/>";<br/>        if(file_exists("upload/")){//用file_exists函数检测是否有upload目录,用if判断。<br/>            if(file_exists("upload/".$_FILES[&#39;file&#39;][&#39;name&#39;])){//用file_exists函数检测是否在upload目录下有[&#39;name&#39;]文件。用if判断。<br/>            echo "已存在该文件名!位置:upload/".$_FILES[&#39;file&#39;][&#39;name&#39;];<br/>        }else{//显示各个信息,然后用move_upload_file函数把临时目录文件移动到upload目录。<br/>            echo "上传完成,下面是信息:<br/>";<br/>            echo "上传文件名:".$_FILES[&#39;file&#39;][&#39;name&#39;]."<br/>";<br/>            echo "上传类型:".$_FILES[&#39;file&#39;][&#39;type&#39;]."<br/>";<br/>            echo "上传文件大小:".$_FILES[&#39;file&#39;][&#39;size&#39;]."<br/>";<br/>            echo "上传文件临时缓存位置:".$_FILES[&#39;file&#39;][&#39;tmp_name&#39;]."<br/>";<br/>            move_uploaded_file($_FILES[&#39;file&#39;][&#39;tmp_name&#39;],"upload/".$_FILES[&#39;file&#39;][&#39;name&#39;]);//这里我们用到两个参数,一是被移到的文件,二是移动到的目标位置。<br/>            echo "储存服务器相对的位置为:/upload/".$_FILES[&#39;file&#39;][&#39;name&#39;];<br/>        }<br/>        }else{//没有目录的情况下,使用mkdir函数创建upload目录。<br/>            echo "不存在upload目录,已自动创建upload/目录";<br/>            mkdir("upload");<br/>        }<br/>    }else{<br/>        echo "扩展名和文件大小不正确,扩展名支持gif,jpg,png,jpeg,文件大小支持200kb";<br/>    }<br/>    //echo "文件临时储存的位置:".$_FILES[&#39;file&#39;][&#39;tmp_name&#39;];//把文件获取到临时储存的位置里面,并打印出来;<br/>    //move_uploaded_file($_FILES[&#39;file&#39;][&#39;tmp_name&#39;],"upload/".$_FILES[&#39;file&#39;][&#39;name&#39;]);//把临时储存的文件移到upload目录下。<br/>}<br/>?><br/>
Copy after login

The background PHP program passes four if judgments to determine the uploaded file four times:

The first if judgment is the uploaded file Whether it is an empty submission or whether there is an error.

The second if determines whether the uploaded file type is correct, whether the extension matches, and whether the size is reasonable.

The third if determines whether the directory to which the uploaded file belongs exists. If it does not exist, the system will automatically create an upload directory using the mkdir function;

The fourth if determines Whether the uploaded file already exists. If it does, it will prompt and stop uploading. On the contrary, if it does not exist, the upload operation will be performed;

The above is the detailed content of How to limit file suffix upload in php. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
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

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 Article

Roblox: Bubble Gum Simulator Infinity - How To Get And Use Royal Keys
3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Nordhold: Fusion System, Explained
3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Mandragora: Whispers Of The Witch Tree - How To Unlock The Grappling Hook
3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Hot Topics

Java Tutorial
1666
14
PHP Tutorial
1273
29
C# Tutorial
1252
24
PHP and Python: Comparing Two Popular Programming Languages PHP and Python: Comparing Two Popular Programming Languages Apr 14, 2025 am 12:13 AM

PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.

PHP: A Key Language for Web Development PHP: A Key Language for Web Development Apr 13, 2025 am 12:08 AM

PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7

PHP in Action: Real-World Examples and Applications PHP in Action: Real-World Examples and Applications Apr 14, 2025 am 12:19 AM

PHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.

PHP vs. Python: Understanding the Differences PHP vs. Python: Understanding the Differences Apr 11, 2025 am 12:15 AM

PHP and Python each have their own advantages, and the choice should be based on project requirements. 1.PHP is suitable for web development, with simple syntax and high execution efficiency. 2. Python is suitable for data science and machine learning, with concise syntax and rich libraries.

The Enduring Relevance of PHP: Is It Still Alive? The Enduring Relevance of PHP: Is It Still Alive? Apr 14, 2025 am 12:12 AM

PHP is still dynamic and still occupies an important position in the field of modern programming. 1) PHP's simplicity and powerful community support make it widely used in web development; 2) Its flexibility and stability make it outstanding in handling web forms, database operations and file processing; 3) PHP is constantly evolving and optimizing, suitable for beginners and experienced developers.

PHP and Python: Code Examples and Comparison PHP and Python: Code Examples and Comparison Apr 15, 2025 am 12:07 AM

PHP and Python have their own advantages and disadvantages, and the choice depends on project needs and personal preferences. 1.PHP is suitable for rapid development and maintenance of large-scale web applications. 2. Python dominates the field of data science and machine learning.

PHP vs. Other Languages: A Comparison PHP vs. Other Languages: A Comparison Apr 13, 2025 am 12:19 AM

PHP is suitable for web development, especially in rapid development and processing dynamic content, but is not good at data science and enterprise-level applications. Compared with Python, PHP has more advantages in web development, but is not as good as Python in the field of data science; compared with Java, PHP performs worse in enterprise-level applications, but is more flexible in web development; compared with JavaScript, PHP is more concise in back-end development, but is not as good as JavaScript in front-end development.

PHP and Python: Different Paradigms Explained PHP and Python: Different Paradigms Explained Apr 18, 2025 am 12:26 AM

PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.

See all articles