php - PHP文件上传确定错误或未选择文件

Question

如何区分用户未选择文件和发生上传错误之间的 PHP 差异？

谢谢

Answer 1

如果上传出错，会有一个文件名。如果没有文件名或没有$_FILES数组，则用户没有选择文件。

Answer 2

如果我没记错的话，我相信你指的是这个

$upload_errors = array(
UPLOAD_ERR_OK =>"No errors.",
UPLOAD_ERR_INI_SIZE => "Larger than upload_max_filesize.",
UPLOAD_ERR_FORM_SIZE => "Larger than form MAX_FILE_SIZE.",
UPLOAD_ERR_PARTIAL => "Partial upload.",
UPLOAD_ERR_NO_FILE => "No file.",
UPLOAD_ERR_NO_TMP_DIR => "No temporary directory.",
UPLOAD_ERR_CANT_WRITE => "Can't write to disk.",
UPLOAD_ERR_EXTENSION => "File upload stopped by extension."
);

$tmp_name = $_FILES['file_upload']['tmp_name'];
$target_file = basename($_FILES['file_upload']['name']);
$upload_dir = "uploads";

if(move_uploaded_file($tmp_name, $upload_dir."/".$target_file)){
    $message = "File uploaded successfully.";

}else{
    $error = $_FILES['file_upload']['error'];
    $message = $upload_errors[$error];
}

Answer 3

如果用户没有选择文件，则该字段将为空，您应该能够进行错误检查

if($_FILES["file"]["name"] != "") { THERE IS A FILE HERE } ELSE { ERROR USER DID NOT SELECT FILE }