Date: Thu, 4 Feb 1999 12:44:46 +1030 From: Greg Lehey <grog@lemis.com> To: Mohamed Abdel-Aal <abdelm2@rpi.edu> Cc: freebsd-questions@FreeBSD.ORG Subject: Re: Kernel I/O, how ? Message-ID: <19990204124446.C1179@freebie.lemis.com> In-Reply-To: <36B90127.241FD3D1@rpi.edu>; from Mohamed Abdel-Aal on Wed, Feb 03, 1999 at 09:08:40PM -0500 References: <36B90127.241FD3D1@rpi.edu>
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On Wednesday, 3 February 1999 at 21:08:40 -0500, Mohamed Abdel-Aal wrote: > I am doing some experiments in TCP that require some modifications to > the code. Namely, /netinet/tcp_timer.c > The problem is that I am not able to do any standard file I/O calls in > the TCP code because I was told that the kernel can't handle high level > I/O calls (stdio.h) . > > All I need to do is open a file, write some stuff to it and then close > it. But I can't do any of this becuase the kernel will not build if > include stdio.h ?? This is probably a question for -hackers, but let's take a quick look at it first. The reason why you can't build the kernel with user-level calls is simply because no mechanism exists to service these calls within the kernel. One way to handle this is to have a user process reading the data from the kernel and then writing it to the file. Create a dummy driver which blocks waiting for data from your tcp code, and read it. Greg -- When replying to this message, please copy the original recipients. For more information, see http://www.lemis.com/questions.html See complete headers for address, home page and phone numbers finger grog@lemis.com for PGP public key To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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