英文:
How to check if an image exists and delete it using PHP
问题
以下是您的内容的中文翻译：
"我已经苦苦挣扎了将近8个小时了。我在我的PHP文件editAuthor.php中有以下代码，允许我在特定目录中上传图像以及其他输入字段。在我的情况下，这个目录是(/uploads/authorAvatars/)。
问题是，当我提交表单时，如果针对特定作者我要编辑的图像已经存在，它不会用我在文件输入框中选择的新图像替换掉它，而是会创建一个新的并将其添加到目录中。所以如果我点击提交按钮5次，它将创建5个图像，而不是一个。图像的文件名存储在表格“authors”的列“avatar”中。
我尝试用PHP检查输入文件是否为空，以便我可以取消链接已存在的图像，但它不起作用。我真的没有主意了。
这是我的代码：
// 处理上传的头像图像if (isset($_FILES['authoravatar']) && $_FILES['authoravatar']['error'] === UPLOAD_ERR_OK ) {$avatarFile = $_FILES['authoravatar'];$authorAvatar = isset($author["avatar"]) ? $author["avatar"] : '';$avatarImage = $avatarDirectory . $authorAvatar;if ($_FILES['authoravatar']['error'] == 4 || ($_FILES['authoravatar']['size'] == 0 && $_FILES['authoravatar']['error'] == 0)) {unlink($avatarImage);}// 提取文件扩展名$fileExtension = pathinfo($avatarFile['name'], PATHINFO_EXTENSION);// 生成头像图像文件名$imageFilename = $authorID . "_avatar_" . basename($avatarFile['name']);// 将上传的文件移动到头像目录$destination = $avatarDirectory . $imageFilename;move_uploaded_file($avatarFile['tmp_name'], $destination);// 使用图像文件名更新头像数据库记录$stmt = $connection->prepare("UPDATE authors SET avatar = ? WHERE id = ?");$stmt->bind_param("si", $imageFilename, $authorID);$stmt->execute();}
我真的完全没有主意了。任何帮助将不胜感激。谢谢。"
英文:
Its been almost 8 hours i am struggling with this. I have the code below in my PHP file editAuthor.php that allows me to upload an image among other input fields in a specific directory. In my case this directory is (/uploads/authorAvatars/).
The problem is that when I submit the form and it is already an existing image for the specific author I edit, instead of replace this image with the new I selected in my input type file, it creates a new one and adds it in the directory. So if I click the submit button 5 times it will create 5 images instead of one. The filename of the image is stored in the column "avatar" of the table "authors".
I tried to check with PHP if the input file is not empty so i can unlink the existed image but it doesn't work. I am really out of ideas.
Here is my code:
// Process the uploaded avatar imageif (isset($_FILES['authoravatar']) && $_FILES['authoravatar']['error'] === UPLOAD_ERR_OK ) {$avatarFile = $_FILES['authoravatar'];$authorAvatar = isset($author["avatar"]) ? $author["avatar"] : '';$avatarImage = $avatarDirectory . $authorAvatar;if ($_FILES['authoravatar']['error'] == 4 || ($_FILES['authoravatar']['size'] == 0 && $_FILES['authoravatar']['error'] == 0)) {unlink($avatarImage);}// Extract the file extension$fileExtension = pathinfo($avatarFile['name'], PATHINFO_EXTENSION);// Generate the avatar image filename$imageFilename = $authorID . "_avatar_" . basename($avatarFile['name']);// Move the uploaded file to the avatar directory$destination = $avatarDirectory . $imageFilename;move_uploaded_file($avatarFile['tmp_name'], $destination);// Update the avatar database record with the image filename$stmt = $connection->prepare("UPDATE authors SET avatar = ? WHERE id = ?");$stmt->bind_param("si", $imageFilename, $authorID);$stmt->execute();}
I am literally running out of ideas. Any help would be very much appreciated. Thanks
答案1
得分: 1
删除现有头像图像文件的条件取决于上传的文件是否无效，所以 unlink 在成功上传时永远不会被调用。
$_FILES['authoravatar']['error'] == 4 // 未上传文件 (UPLOAD_ERR_NO_FILE)// 或者$_FILES['authoravatar']['error'] == 0 // 文件上传时没有错误 (UPLOAD_ERR_OK)$_FILES['authoravatar']['size'] == 0 // 上传的文件为空
操作顺序应确保文件已成功保存。
if (isset($_FILES['authoravatar']) && $_FILES['authoravatar']['error'] === UPLOAD_ERR_OK) {$avatarFile = $_FILES['authoravatar'];// 生成头像图像文件名$imageFilename = $authorID . '_avatar_' . basename($avatarFile['name']);// 将上传的文件移动到头像目录$destination = $avatarDirectory . $imageFilename;$isSaved = move_uploaded_file($avatarFile['tmp_name'], $destination);if ($isSaved) {// 使用图像文件名更新头像数据库记录$stmt = $connection->prepare('UPDATE authors SET avatar = ? WHERE id = ?');$stmt->bind_param('si', $imageFilename, $authorID);$stmt->execute();// 验证来自作者数据的现有头像if (isset($author["avatar"])) {$avatarImage = $avatarDirectory . $author['avatar'];// 确保文件存在且目录具有写入权限if (is_file($avatarImage) && is_writable(dirname($avatarImage))) {// 从文件系统中删除旧头像图像unlink($avatarImage);}}}}
如果意图是在 file 表单字段为空时删除现有头像图像文件，您需要额外的 unlink 调用。
if (!isset($_FILES['authoravatar']) ||UPLOAD_ERR_NO_FILE === $_FILES['authoravatar']['error'] ||0 === $_FILES['authoravatar']['size']) {// 验证来自作者数据的现有头像if (isset($author["avatar"])) {$avatarImage = $avatarDirectory . $author['avatar'];// 确保文件存在且目录具有写入权限if (is_file($avatarImage) && is_writable(dirname($avatarImage))) {// 从文件系统中删除旧头像图像unlink($avatarImage);}}}
英文:
The condition to delete the existing avatar image file is contingent on the uploaded file being invalid, so unlink will never be called during a successful upload.
$_FILES['authoravatar']['error'] == 4 // no file uploaded (UPLOAD_ERR_NO_FILE)// or$_FILES['authoravatar']['error'] == 0 // no error during file upload (UPLOAD_ERR_OK)$_FILES['authoravatar']['size'] == 0 // uploaded file was empty
The order of operations should ensure that the file was saved successfully as well.
if (isset($_FILES['authoravatar']) && $_FILES['authoravatar']['error'] === UPLOAD_ERR_OK) {$avatarFile = $_FILES['authoravatar'];// Generate the avatar image filename$imageFilename = $authorID . '_avatar_' . basename($avatarFile['name']);// Move the uploaded file to the avatar directory$destination = $avatarDirectory . $imageFilename;$isSaved = move_uploaded_file($avatarFile['tmp_name'], $destination);if ($isSaved) {// Update the avatar database record with the image filename$stmt = $connection->prepare('UPDATE authors SET avatar = ? WHERE id = ?');$stmt->bind_param('si', $imageFilename, $authorID);$stmt->execute();// verify pre-existing avatar from Author dataif (isset($author["avatar"])) {$avatarImage = $avatarDirectory . $author['avatar'];// ensure a file exists and the directory has permissionsif (is_file($avatarImage) && is_writable(dirname($avatarImage))) {// delete the old avatar image from the filesystemunlink($avatarImage);}}}}
If the intention is to delete the existing avatar image file when the file form field is empty, you would need an additional unlink call.
if (!isset($_FILES['authoravatar']) ||UPLOAD_ERR_NO_FILE === $_FILES['authoravatar']['error'] ||0 === $_FILES['authoravatar']['size']) {// verify pre-existing avatar from Author dataif (isset($author["avatar"])) {$avatarImage = $avatarDirectory . $author['avatar'];// ensure a file exists and the directory has permissionsif (is_file($avatarImage) && is_writable(dirname($avatarImage))) {// delete the old avatar image from the filesystemunlink($avatarImage);}}}
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