如何在php中将上传的文件发送到电子邮件

<?php
// 设置收件人和主题
$to = "recipient@example.com";
$subject = "上传文件";

// 获取上传文件的相关信息
$file = $_FILES['file'];
$fileName = $file['name'];
$fileTmpPath = $file['tmp_name'];

// 构建邮件内容
$message = "这是一个上传的文件，请查收。";
$boundary = md5(time());
$headers = "From: sender@example.com\r\n";
$headers .= "MIME-Version: 1.0\r\n";
$headers .= "Content-Type: multipart/mixed; boundary=\"" . $boundary . "\"\r\n";
$body = "--" . $boundary . "\r\n";
$body .= "Content-Type: text/plain; charset=\"utf-8\"\r\n";
$body .= "Content-Transfer-Encoding: 7bit\r\n\r\n";
$body .= $message . "\r\n";
$body .= "--" . $boundary . "\r\n";
$body .= "Content-Type: application/octet-stream; name=\"" . $fileName . "\"\r\n";
$body .= "Content-Transfer-Encoding: base64\r\n";
$body .= "Content-Disposition: attachment; filename=\"" . $fileName . "\"\r\n\r\n";
$body .= chunk_split(base64_encode(file_get_contents($fileTmpPath))) . "\r\n";
$body .= "--" . $boundary . "--";

// 发送邮件
if (mail($to, $subject, $body, $headers)) {
    echo "文件已成功发送到电子邮件。";
} else {
    echo "发送邮件失败，请检查配置。";
}
?>