Jinsi ya Kufanya File Type na Size Validation

File validation inahakikisha:

User hawezi kupakia files zisizo halali au hatari.

Ukubwa wa file hauzidi limit uliowekwa.

System inabaki salama kutokana na malicious uploads.

Validation inafanywa kabla ya move_uploaded_file().

⚙️ 2. HTML Form ya File Upload

enctype="multipart/form-data" lazima iwe.

name="uploaded_file" ni input tunalotumia PHP.

🧩 3. PHP Script ya File Validation

$max_size){
die("❌ Error: File too large. Max 5MB allowed.");
}

// Move file
if(move_uploaded_file($_FILES['uploaded_file']['tmp_name'], $target_file)){
echo "✅ File uploaded successfully:

";
} else {
echo "❌ Error uploading file.";
}
}
?>

💡 Maelezo:

in_array() inakagua file extension.

$_FILES['uploaded_file']['size'] inakagua size.

time() . "_" . $file_name inazalisha unique filename.

🔑 4. Vidokezo vya Usalama Zaidi

Check MIME type optionally – mime_content_type() kwa extra security.

Store files outside web root – avoid direct access.

Rename files – prevent overwriting & execution.

Limit folder permissions – usually 0755.

Avoid uploading scripts – .php, .js kwenye public folder.

✅ 5. Hitimisho

File type na size validation ni must-have kwa secure uploads.

Combine na authentication & CSRF tokens kwa web security zaidi.

Best practices: validate type & size, unique filenames, secure directory, avoid scripts.

🔗 Tembelea:

👉 https://www.faulink.com/

Kwa mafunzo zaidi ya PHP, file handling, na secure web application development.