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php实现文件传输

2026-02-14 04:11:35PHP

PHP实现文件上传

使用PHP的$_FILES超全局变量处理文件上传，表单需设置enctype="multipart/form-data"属性。

<form action="upload.php" method="post" enctype="multipart/form-data">
    <input type="file" name="fileToUpload">
    <input type="submit" value="Upload">
</form>

PHP处理脚本示例：

$targetDir = "uploads/";
$targetFile = $targetDir . basename($_FILES["fileToUpload"]["name"]);
move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $targetFile);

PHP实现文件下载

通过设置HTTP头实现文件下载：

$filePath = 'path/to/file.ext';
header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename="'.basename($filePath).'"');
readfile($filePath);
exit;

大文件分块传输

对于大文件传输，可采用分块处理方式：

// 上传分块处理
$chunk = $_FILES['file']['tmp_name'];
$chunkNumber = $_POST['chunk'];
$totalChunks = $_POST['totalChunks'];

// 下载分块处理
$file = 'large_file.zip';
$chunkSize = 1024 * 1024; // 1MB
$handle = fopen($file, 'rb');
fseek($handle, $_GET['offset']);
echo fread($handle, $chunkSize);

安全注意事项

验证文件类型和大小：

$allowedTypes = ['image/jpeg', 'image/png'];
$maxSize = 5 * 1024 * 1024; // 5MB

if (!in_array($_FILES['file']['type'], $allowedTypes)) {
    die('Invalid file type');
}

if ($_FILES['file']['size'] > $maxSize) {
    die('File too large');
}

存储上传文件时使用随机文件名：

php实现文件传输

$extension = pathinfo($_FILES['file']['name'], PATHINFO_EXTENSION);
$newFilename = uniqid().'.'.$extension;
move_uploaded_file($_FILES['file']['tmp_name'], 'uploads/'.$newFilename);