What are the best practices for handling file extensions and file manipulation in PHP?

When handling file extensions and file manipulation in PHP, it is important to validate and sanitize user input to prevent security vulnerabilities such as file inclusion attacks. To ensure that files are handled safely, always use built-in PHP functions like pathinfo() to extract file extensions and check against a whitelist of allowed extensions before performing any file operations. 

// Example of validating and handling file extensions in PHP

$allowedExtensions = ['jpg', 'png', 'pdf']; // Define a whitelist of allowed file extensions

$filename = 'myfile.jpg'; // Example filename

$extension = pathinfo($filename, PATHINFO_EXTENSION); // Get the file extension

if (in_array($extension, $allowedExtensions)) {
    // File extension is allowed, proceed with file manipulation
    // Your file manipulation code here
} else {
    // File extension is not allowed, handle error or reject the file
    echo 'Invalid file extension.';
}

Keywords

file extensions file manipulation PHP functions error handling security

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