如何用php压缩上传文件

<code class="php">$file = $_FILES['file'];</code>

<code class="php">$fileExtension = pathinfo($file['name'], PATHINFO_EXTENSION);</code>

<code class="php">if ($fileExtension == 'jpg' || $fileExtension == 'jpeg') {
    $compressor = 'imagecreatefromjpeg';
    $output = 'imagejpeg';
} elseif ($fileExtension == 'png') {
    $compressor = 'imagecreatefrompng';
    $output = 'imagepng';
} elseif ($fileExtension == 'gif') {
    $compressor = 'imagecreatefromgif';
    $output = 'imagegif';
}</code>

<code class="php">$srcImage = $compressor($file['tmp_name']);
$quality = 75; // 压缩质量，取值范围 0-100
$newImage = imagecreatetruecolor(imagesx($srcImage), imagesy($srcImage));
imagecopyresampled($newImage, $srcImage, 0, 0, 0, 0, imagesx($newImage), imagesy($newImage), imagesx($srcImage), imagesy($srcImage));
ob_start();
$output($newImage);
$compressedData = ob_get_clean();</code>

<code class="php">$compressedFile = fopen('compressed-' . $file['name'], 'wb');
fwrite($compressedFile, $compressedData);
fclose($compressedFile);</code>