Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Delivered-To: mailing list cygwin@cygwin.com To: cygwin@cygwin.com From: Eric Blake Subject: POSIX compliance of unlink(2) Date: Mon, 28 Feb 2005 22:45:59 +0000 (UTC) Lines: 61 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Complaints-To: usenet@sea.gmane.org X-Gmane-NNTP-Posting-Host: main.gmane.org User-Agent: Loom/3.14 (http://gmane.org/) X-Loom-IP: 128.170.36.44 (Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; .NET CLR 1.1.4322)) X-Gmane-MailScanner: Found to be clean X-Gmane-MailScanner: Found to be clean X-MailScanner-From: goc-cygwin@m.gmane.org X-MailScanner-To: cygwin@cygwin.com X-IsSubscribed: yes 1.5.12 and the latest snapshots allow unlinking a file contrary to POSIX rules. The addition of CYGWIN=traverse was not enough to fix this issue. Unlink is required to fail with EACCES if the file is contained in a directory without write permission. $ mkdir a $ touch a/b $ chmod a-w a $ touch a/c # Correctly fails touch: cannot touch `a/c': Permission denied $ rm a/b # Oops, should have failed $ Furthermore, unlink should touch the ctime of the containing directory, and the ctime of the unlink'd file (if hard links remain after the unlink succeeds). In general, open(O_CREAT), link, rename, mkdir, and rmdir should touch the ctime of the containing directory when the directory's contents change. $ stat . File: `.' Size: 12288 Blocks: 12 IO Block: 1024 directory Device: 10292fb1h/271134641d Inode: 3390366094479868980 Links: 13 Access: (0777/drwxrwxrwx) Uid: ( 544/Administrators) Gid: (10513/Domain Users) Access: 2005-02-28 15:25:36.990625000 -0700 Modify: 2005-02-28 15:25:32.350000000 -0700 Change: 2005-02-28 15:24:58.756250000 -0700 $ mkdir a # Oops, ctime of . not affected $ touch b # Oops, ctime of . not affected $ ln b c # Oops, ctime of . not affected (but correctly touches b and c) $ stat c File: `c' Size: 0 Blocks: 0 IO Block: 1024 regular empty file Device: 10292fb1h/271134641d Inode: 2251799813814789 Links: 1 Access: (0666/-rw-rw-rw-) Uid: (22382/ eblake) Gid: (10513/Domain Users) Access: 2005-02-28 15:28:25.584375000 -0700 Modify: 2005-02-28 15:28:25.584375000 -0700 Change: 2005-02-28 15:28:28.225000000 -0700 $ rmdir a # Oops, ctime of . not affected $ rm b # Oops, ctime of . and c not affected $ mv c a # Oops, ctime of . not affected $ stat . a File: `.' Size: 12288 Blocks: 12 IO Block: 1024 directory Device: 10292fb1h/271134641d Inode: 3390366094479868980 Links: 13 Access: (0777/drwxrwxrwx) Uid: ( 544/Administrators) Gid: (10513/Domain Users) Access: 2005-02-28 15:28:40.850000000 -0700 Modify: 2005-02-28 15:28:40.850000000 -0700 Change: 2005-02-28 15:24:58.756250000 -0700 File: `a' Size: 0 Blocks: 0 IO Block: 1024 regular empty file Device: 10292fb1h/271134641d Inode: 2251799813814789 Links: 1 Access: (0666/-rw-rw-rw-) Uid: (22382/ eblake) Gid: (10513/Domain Users) Access: 2005-02-28 15:28:25.584375000 -0700 Modify: 2005-02-28 15:28:25.584375000 -0700 Change: 2005-02-28 15:28:28.225000000 -0700 -- Eric Blake -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/