What are some best practices for handling file uploads and processing in PHP?

When handling file uploads and processing in PHP, it is important to validate the file type, size, and name to prevent security vulnerabilities. Additionally, always move uploaded files to a secure directory outside of the web root to prevent direct access. Lastly, sanitize user input to prevent any potential injection attacks. 

// Example code snippet for handling file uploads in PHP

// Check if file was uploaded without errors
if(isset($_FILES['file']) && $_FILES['file']['error'] == UPLOAD_ERR_OK) {
    
    // Validate file type
    $allowedTypes = ['image/jpeg', 'image/png'];
    if(in_array($_FILES['file']['type'], $allowedTypes)) {
        
        // Validate file size
        if($_FILES['file']['size'] < 5000000) {
            
            // Move uploaded file to secure directory
            $uploadPath = '/path/to/secure/directory/' . basename($_FILES['file']['name']);
            move_uploaded_file($_FILES['file']['tmp_name'], $uploadPath);
            echo 'File uploaded successfully!';
            
        } else {
            echo 'File size is too large!';
        }
        
    } else {
        echo 'Invalid file type!';
    }
    
} else {
    echo 'Error uploading file!';
}

Keywords

file uploads processing PHP security error handling

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