Mailing-List: contact cygwin-help@sourceware.cygnus.com; run by ezmlm List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@sources.redhat.com Delivered-To: mailing list cygwin@sources.redhat.com Date: Wed, 23 May 2001 19:25:40 -0400 From: Christopher Faylor To: cygwin@cygwin.com Cc: nelson@reversion.ca Subject: Re: cygwin_attach_handle_to_fd() Message-ID: <20010523192540.A15862@redhat.com> Reply-To: cygwin@cygwin.com Mail-Followup-To: cygwin@cygwin.com, nelson@reversion.ca References: <3B0C35D4.5B3849D0@reversion.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.11i In-Reply-To: <3B0C35D4.5B3849D0@reversion.ca>; from nelson@reversion.ca on Wed, May 23, 2001 at 04:12:36PM -0600 On Wed, May 23, 2001 at 04:12:36PM -0600, Craig Nelson wrote: >Hi All, just looking for a bit more info on >cygwin_attach_handle_to_fd(): the API references shows it as: > >----snip---- >extern "C" int cygwin_attach_handle_to_fd(char *name, int fd, HANDLE handle, int bin, int access); > >This function can be used to turn a Win32 "handle" into a posix-style >file handle. fd may be -1 to make cygwin allocate a handle; the actual >handle is returned in all cases. > >----snip---- > >But I'm wondering what kinds of values BIN, ACCESS, and NAME are expected to have. In particular: > > -Does NAME have to be a unique string? if so, unique amongst each invocation of a cygwin process, etc. > -Should BIN be set to unix things like O_BINARY | O_RDONLY or win32 things like GENERIC_READ, etc. > -Should ACCESS be set to unix things like S_IRWXU or win32 things like FILE_SHARE_READ, etc. > >Any help on all the options for this function would be greatly appreciated. From inspecting the code: 'name' is the name of the file or device. 'bin' is true if the file should be opened in binary mode, false for text mode. 'access' is a windows setting like 'GENERIC_READ' or 'GENERIC-WRITE'. >Incase anybody is wondering why I'm needing this: The reason is, I'm >using CreateProcess(), CreatePipe() and cygwin_attach_handle_to_fd() in >order to start up a child process and redirect its STDIN, STDOUT, and >STDERR and use it in my program. It works great except the fd returned >from attach_handle() appears to never get closed (and therfore read() >blocks indefinately because it never gets an EOF). It sounds like you're reinventing "popen" to me. >I've tried setting BIN and ACCESS to constants shown above (without >success), and I am wondering If there's something I've not set. I'm >running NT4sp6a with the latest cygwin-1.3.2 release. please send a >reply to nelson@reversion.ca (and the list, if desired) Probably the best thing you could do is inspect the source code. That's what I just did. cgf -- Want to unsubscribe from this list? Check out: http://cygwin.com/ml/#unsubscribe-simple