PHP文件上传确定错误或没有选择文件

Question

如何判断用户未选择文件和发生上传错误时PHP的差异？

谢谢

Answer 1

如果用户没有选择文件中的字段将是空的，你应该能够对错误检查

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

Answer 2

如果出现错误上传，将会有一个文件名。如果没有文件名或$_FILES数组，则用户没有选择文件。

Answer 3

如果我没有记错的话，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]; 
}