X-Recipient: archive-cygwin@delorie.com X-Spam-Check-By: sourceware.org X-ME-UUID: 20071012094526780.BE59C1C00095@mwinf2529.orange.fr Message-ID: <470F4239.8090808@prologue.fr> Date: Fri, 12 Oct 2007 11:45:29 +0200 From: patrick ficheux User-Agent: Thunderbird 2.0.0.6 (Windows/20070728) MIME-Version: 1.0 To: cygwin@cygwin.com Subject: Re: shmget() returns xx if current user is not a administrator References: <470F39C7.2010006@prologue.fr> <20071012093046.GF20400@calimero.vinschen.de> In-Reply-To: <20071012093046.GF20400@calimero.vinschen.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-IsSubscribed: yes Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm List-Id: 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 Corinna Vinschen a écrit : > On Oct 12 11:09, patrick ficheux wrote: > >> In SANE (scanner project), the backend for snapscan failed to call shmget() >> with error EACCES (Permission denied) if the current user isn't >> administrator. >> When I'am logged as windows administrator, shmget() is called successfully >> >> In both case, the env. variable CYGWIN exists and this value is >> CYGWIN=server >> cygserver is installed and runs >> >> >> Is it possible to call shmget() without administrator's privileges ? >> In this case, what kind of privileges a user must have ? and how to set >> those privileges ? >> >> Thanks >> >> extract from snapscan backend >> >> #ifndef SHM_R >> #define SHM_R 0 >> #endif >> >> #ifndef SHM_W >> #define SHM_W 0 >> #endif >> > > ^^^^^^^^^^^^^^^^^^^^ > This is the problem. SHM_R and SHM_W are not defined on Cygwin. > These flags are not defined by POSIX and relying on them as above is > non-portable. As a result, you create a shared mem region with > permission bits set to 000. > > >> int shm_id = shmget (IPC_PRIVATE, shm_size, IPC_CREAT | SHM_R | SHM_W); >> > > Try something like > > #include > int shm_id = shmget (IPC_PRIVATE, shm_size, IPC_CREAT | S_IRWXU); > it works fine ! thanks a lot -- 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/