X-Recipient: archive-cygwin AT delorie DOT com X-Spam-Check-By: sourceware.org Date: Sun, 30 May 2010 19:51:00 -0400 From: Christopher Faylor To: cygwin AT cygwin DOT com Subject: Re: Reading /proc/registry/... returns extra char Message-ID: <20100530235100.GD21673@ednor.casa.cgf.cx> Reply-To: cygwin AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com References: <20100513181249 DOT GE13784 AT cupro DOT opengvs DOT com> <2BF01EB27B56CC478AD6E5A0A28931F2F01D44 AT A1DAL1SWPES19MB DOT ams DOT acs-inc DOT net> <20100526114733 DOT GG10652 AT calimero DOT vinschen DOT de> <1254830174 DOT 20100526174227 AT mtu-net DOT ru> <20100526143428 DOT GN10652 AT calimero DOT vinschen DOT de> <326990670 DOT 20100530001515 AT mtu-net DOT ru> <20100530055757 DOT GA3251 AT trixie DOT casa DOT cgf DOT cx> <1656998784 DOT 20100531033519 AT mtu-net DOT ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1656998784.20100531033519@mtu-net.ru> User-Agent: Mutt/1.5.20 (2009-06-14) Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner AT cygwin DOT com Mail-Followup-To: cygwin AT cygwin DOT com Delivered-To: mailing list cygwin AT cygwin DOT com On Mon, May 31, 2010 at 03:35:19AM +0400, Andrey Repin wrote: >Greetings, Christopher Faylor! >>>>> >> > $ cat >a.dat >>>>> >> > /proc/registry/HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Control/Syst >>>>> >> > emBootDevice >>>>> >>>>> > This trailing NUL character was always there, already with Cygwin 1.5. >>>>> > It's part of the file content. If strings are stored with a trailing >>>>> > NUL in a file, you don't want Cygwin to remove it for you, right? >>>>> >>>>> Wrong. The training NULL is a string value terminator for REG_SZ variables, >>>>> also a string separator for REG_MULTI_SZ ones. (Which ends with a spare NULL) >>>>> It must not be exposed to the user. >>> >>>> I disagree. When you're using tools like regtool, you're right. But >>>> when accessing the registry as *files* via the virtual /proc filesystem, >>>> you want the file content. >>> >>>Yep. And I certainly not expect the NULL in text files. You know, not every >>>console program is binary-safe when working with STDIO? Not even cygwin, as we >>>can see in this thread. >>> >>>> And the file contains the trailing NUL in REG_SZ and REG_EXPAND_SZ values, >>>> and multiple NULs in REG_MULTI_SZ values. >>> >>>That's right and true, when you're working with interface directly, but... all >>>the programs I've used in the past, and all the interfaces, they do not expose >>>trailing NULL to the client application. >>>In this case, /proc/registry is an interface, but cat is the application. > >> NAME >> cat - concatenate files and print on the standard output > >> I don't see anything in cat's description which claims it should know >> that some files are special and should be handled differently. > >I didn't said about cat, but rather about file it reading from. > >>>> What do you suppose Cygwin should do with the NULs in REG_MULTI_SZ values? >>>> Just remove them? >>> >>>Convert them to appropriate EOL sequences. And back to NULL's on write. As per >>>definition of a text as "multiple strings". >>>You don't need to argue over it, just document it properly :) > >> Converting a NUL to a EOL would be very strange behavior. > >Strange? I don't think so. I expect text data from text file. Not binary >stream. > >> I don't think you really know what you're asking for. > >I know. Look at windows own regedit and Registry Browser FAR plugin as two >examples. >They do such two-way conversion transparently for user. Ok. I'm done trying to educate. We're not going to be changing Cygwin unless we find that there is a bug in its representation of the data in /proc/registry. If the data is being exactly represented as it is retrieved from the registry API, it is not a bug. Even if there is a bug, we are not going to be translating NUL to EOL. I'm fairly confident that Corinna will back me up on that. cgf -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple