What are the advantages and disadvantages of using pathinfo or regular expressions to check file extensions when processing uploaded files in PHP?

When processing uploaded files in PHP, it is important to check the file extension to ensure it is allowed and safe. Two common methods to do this are using pathinfo or regular expressions. Using pathinfo is simpler and more straightforward, as it directly extracts the file extension from the file name. However, regular expressions offer more flexibility and control over the validation process. Here is a PHP code snippet that demonstrates how to use pathinfo to check file extensions: 

$allowedExtensions = ['jpg', 'png', 'gif'];
$fileName = $_FILES['file']['name'];
$extension = pathinfo($fileName, PATHINFO_EXTENSION);

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

Keywords

pathinfo regular expressions file extensions uploaded files PHP

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