Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755023AbbBCJzT (ORCPT ); Tue, 3 Feb 2015 04:55:19 -0500 Received: from mail-la0-f43.google.com ([209.85.215.43]:57765 "EHLO mail-la0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751570AbbBCJzQ (ORCPT ); Tue, 3 Feb 2015 04:55:16 -0500 MIME-Version: 1.0 Reply-To: mtk.manpages@gmail.com In-Reply-To: <87fvane3ch.fsf@mail.parknet.co.jp> References: <1422042884-10824-1-git-send-email-xypron.glpk@gmx.de> <87k2zze5tg.fsf@mail.parknet.co.jp> <87fvane3ch.fsf@mail.parknet.co.jp> From: "Michael Kerrisk (man-pages)" Date: Tue, 3 Feb 2015 10:54:53 +0100 Message-ID: Subject: Re: [PATCH v3 1/1] ioctl-fat.2: new manpage for the ioctl fat API To: OGAWA Hirofumi Cc: Heinrich Schuchardt , "linux-fsdevel@vger.kernel.org" , lkml , linux-man Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2233 Lines: 65 Hello Hirofumi, On 3 February 2015 at 10:44, OGAWA Hirofumi wrote: > "Michael Kerrisk (man-pages)" writes: > >>> Quick reviewed, and looks good. However, entry[0].d_reclen == 0 works as >>> backward compatibility though. The example might be good to use usual >>> way of getdents(). >>> >>> I.e., "ret" means >>> -1 == error >>> 0 == EOD >>> 0 > how many bytes read >> >> Sorry -- I do not really understand what you mean here >> "entry[0].d_reclen == 0 works as backward compatibility though"). Is >> the line >> >> if (ret == -1 || entry[0].d_reclen == 0) >> >> incorrect? If yes, what should the code look like? > > Sorry. I meant, "entry[0].d_reclen == 0" check works because fatfs still > have backward compatibility code. However it would not be preferred way. > > In ancient version, fatfs didn't return proper return code, so apps (I > know only use is wine) had to check "entry[0].d_reclen == 0" to know > EOD. > > But for a long time, fatfs returns proper return code like said in > previous email (previous email was wrong on "0 > how many bytes read", > see below instead). I.e., now user can use "ret" as similar to > getdents(), user can know the result as usual from "ret" without > "entry[0].d_reclen == 0". > > while (1) { > ret = ioctl(); > if (ret == -1) { > /* error */ > > if (ret == 0) > /* EOD */ > > /* got entry (would be ret == 1) */ > } Thanks for the clarification. I have one other question. Currently the man page does not document two fields in the __fat_dirent structure: d_ino and d_offset. d_ino is presumably the inode number. But, what is d_offset? Cheers, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/