在Ubuntu上使用PHP实现文件上传，你需要遵循以下步骤：
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>File Upload</title> </head> <body> <form action="upload.php" method="post" enctype="multipart/form-data"> Select file to upload: <input type="file" name="fileToUpload" id="fileToUpload"> <input type="submit" value="Upload File" name="submit"> </form> </body> </html> upload.php的PHP文件，用于处理文件上传：<?php $target_dir = "uploads/"; $target_file = $target_dir . basename($_FILES["fileToUpload"]["name"]); $uploadOk = 1; $imageFileType = strtolower(pathinfo($target_file,PATHINFO_EXTENSION)); // Check if image file is an actual image or fake image if(isset($_POST["submit"])) { $check = getimagesize($_FILES["fileToUpload"]["tmp_name"]); if($check !== false) { echo "File is an image - " . $check["mime"] . "."; $uploadOk = 1; } else { echo "File is not an image."; $uploadOk = 0; } } // Check if file already exists if (file_exists($target_file)) { echo "Sorry, file already exists."; $uploadOk = 0; } // Check file size if ($_FILES["fileToUpload"]["size"] > 500000) { echo "Sorry, your file is too large."; $uploadOk = 0; } // Allow certain file formats if($imageFileType != "jpg" && $imageFileType != "png" && $imageFileType != "jpeg" && $imageFileType != "gif" ) { echo "Sorry, only JPG, JPEG, PNG & GIF files are allowed."; $uploadOk = 0; } // Check if $uploadOk is set to 0 by an error if ($uploadOk == 0) { echo "Sorry, your file was not uploaded."; // if everything is ok, try to upload file } else { if (move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $target_file)) { echo "The file ". htmlspecialchars( basename( $_FILES["fileToUpload"]["name"])). " has been uploaded."; } else { echo "Sorry, there was an error uploading your file."; } } ?> 确保uploads目录存在并具有适当的权限，以便PHP脚本可以将文件上传到该目录。在终端中运行以下命令：
sudo mkdir uploads sudo chmod 755 uploads 将HTML文件保存为index.html，并将PHP文件保存为upload.php。将这两个文件放在你的Web服务器的根目录（例如/var/www/html）中。然后，在浏览器中访问http://your_server_ip/index.html，你应该能够看到文件上传表单。选择一个文件并单击“上传文件”按钮，文件将被上传到uploads目录。
注意：在生产环境中，你可能需要考虑更多的安全措施，例如检查用户输入、限制上传文件的大小和类型以及使用更安全的文件名。
