你好所以我有以下代码..functionexport_file(){$tmpname='/tmp/'.sha1(uniqid()).$ext;$filename='export.sql';$cmd=sprintf("/Applications/XAMPP/xamppfiles/bin/mysqldump-h'%s'-u'%s'-p'%s'%s--single-transaction%s>%s",DB_HOST,DB_USER,DB_PASSWORD,DB_NAME,$compression_pipe,$tmpname);exec($cmd);header('Content-Type:a