From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3e1162e60607111450p5361d664pe38a361c15faba6e@mail.gmail.com> Date: Tue, 11 Jul 2006 14:50:56 -0700 From: "David Leimbach" To: "Fans of the OS Plan 9 from Bell Labs" <9fans@cse.psu.edu> Subject: Re: [9fans] Which thing was harder for u to grasp relating Plan 9? In-Reply-To: <8ccc8ba40607111152p228bc378i7b34b5f24baa036f@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Content-Disposition: inline References: <8ccc8ba40607111152p228bc378i7b34b5f24baa036f@mail.gmail.com> Topicbox-Message-UUID: 7ce3fd72-ead1-11e9-9d60-3106f5b1d025 On 7/11/06, Francisco J Ballesteros wrote: > I=B4m writing a book for the introductory course in OS at urjc, that > we teach using Plan 9. Most of it is a a lot of generic introductory > stuff about the system. > > I=B4d love to know the top-10 of "hard-to-get" concepts about the system, > specially for new comers, > to try to cover them. > > thanks a lot in any case. > You might consider talking about filesystems and read/write as RPC mechanisms. I don't think people really got that or get that today. Look at FreeBSD with it's blahctl programs for every device. Having the ability to talk to a mounted file for control simplifies a lot of things. Might want to compare such a concept to /proc on linux though I think they even overcomplicated /proc there. (see the miscellaneous binary format support that's available) A potentially good example about the power of the filesystem as a control interface would probably be burning a CD in Plan 9. That could cover a lot of "neat stuff" like the 9660srv program. I had fun playing with eia serial access and control myself at home too. Also, there was my experience trying to add an option to Rio to deal with the fact that I didn't like the labels I was getting for "rio in rio" sessions. Russ Cox straightened me out, and I got to throw away some new C code I didn't really want to maintain anyway. http://mordor.tip9ug.jp/who/leimy/session.html That was a very enightening experience for me. A lot more system behavior could be changed through the filesystem and new applications of things like /dev/null than I had actually imagined. It was a real brain-stretcher. (not a gurney... that's linux). Dave