thinkphp 获取文件扩展名

$file = 'example.txt';
$path_info = pathinfo($file);
$extension = $path_info['extension']; // 获取扩展名
echo $extension; // 输出: txt

$file = 'example.txt';
$extension = array_pop(explode('.', $file)); // 获取扩展名
echo $extension; // 输出: txt

use think\facade\Filesystem;

$file = 'example.txt';
$extension = Filesystem::getInfo($file, 'type'); // 获取扩展名
echo $extension; // 输出: txt

$file = 'example.txt';
if (strpos($file, '.') !== false) {
    $path_info = pathinfo($file);
    $extension = $path_info['extension'];
    echo $extension;
} else {
    echo '文件名中没有扩展名';
}

$file = 'example.tar.gz';
$path_info = pathinfo($file, PATHINFO_EXTENSION);
echo $path_info; // 输出: gz