Comments on: Dear Lazyweb: FD passing on Win32? How? http://dossy.org/2006/02/dear-lazyweb-fd-passing-on-win32-how/ Everything that comes out of Dossy, from the strange to the banal. Fri, 27 Jan 2012 14:30:11 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Jamie Rasmussen http://dossy.org/2006/02/dear-lazyweb-fd-passing-on-win32-how/comment-page-1/#comment-286 Jamie Rasmussen Thu, 09 Feb 2006 06:20:53 +0000 http://dossy.org/archives/000224.html#comment-286 I think several forms of interprocess communication would work, it depends on your situation. Named pipe is an option. I'm assuming the processes are unrelated, since a child process can inherit handles from the parent - it's a parameter of CreateProcess. I haven't ever needed to do this with unrelated processes, so I hope it works. :-) I think several forms of interprocess communication would work, it depends on your situation. Named pipe is an option. I’m assuming the processes are unrelated, since a child process can inherit handles from the parent – it’s a parameter of CreateProcess. I haven’t ever needed to do this with unrelated processes, so I hope it works. :-)

]]> By: Dossy http://dossy.org/2006/02/dear-lazyweb-fd-passing-on-win32-how/comment-page-1/#comment-285 Dossy Wed, 08 Feb 2006 13:15:57 +0000 http://dossy.org/archives/000224.html#comment-285 You know, I looked at _get_osfhandle and _open_osfhandle, but I totally missed <a href="http://msdn.microsoft.com/library/default.asp?url=/library/en-us/sysinfo/base/duplicatehandle.asp">DuplicateHandle</a>. On the MSDN Library page for DuplicateHandle, it says: <i>"If the process that calls <b>DuplicateHandle</b> is not also the target process, the source process must use interprocess communication to pass the value of the duplicate handle to the target process."</i> So, I'd use a pipe and write the value of the duplicated handle across to the child process? I guess coming from Unix, the notion that one process can duplicate a filehandle into another process's space is ... unsettling. :-) Thanks for the pointer, Jamie. You're the best. You know, I looked at _get_osfhandle and _open_osfhandle, but I totally missed DuplicateHandle.

On the MSDN Library page for DuplicateHandle, it says:

“If the process that calls DuplicateHandle is not also the target process, the source process must use interprocess communication to pass the value of the duplicate handle to the target process.”

So, I’d use a pipe and write the value of the duplicated handle across to the child process? I guess coming from Unix, the notion that one process can duplicate a filehandle into another process’s space is … unsettling. :-)

Thanks for the pointer, Jamie. You’re the best.

]]> By: Jamie Rasmussen http://dossy.org/2006/02/dear-lazyweb-fd-passing-on-win32-how/comment-page-1/#comment-284 Jamie Rasmussen Wed, 08 Feb 2006 05:50:59 +0000 http://dossy.org/archives/000224.html#comment-284 Have you tried a sequence like: _get_osfhandle -> DuplicateHandle -> _open_osfhandle? Have you tried a sequence like:
_get_osfhandle -> DuplicateHandle -> _open_osfhandle?

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