From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <13426df10611201832m7ce46730pf61df2e78d544e14@mail.gmail.com> Date: Mon, 20 Nov 2006 19:32:49 -0700 From: "ron minnich" To: "Fans of the OS Plan 9 from Bell Labs" <9fans@cse.psu.edu> Subject: Re: [9fans] Re: echo -n In-Reply-To: <0F431F87-7799-4D4C-8302-D2CA6286AAC3@ar.aichi-u.ac.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <1c5b7c3fd84e9c2449747b93b99abf66@coraid.com> <7B16F5E3-CF10-4603-9D4E-557BA4A493EF@telus.net> <13426df10611201627g1d8e0962wf512a11aca15bfc7@mail.gmail.com> <0F431F87-7799-4D4C-8302-D2CA6286AAC3@ar.aichi-u.ac.jp> Topicbox-Message-UUID: e3f08e2c-ead1-11e9-9d60-3106f5b1d025 This whole discussion has been coming up for years. I can't remember the first time I saw it but it was definitely over a quarter century ago. I think at some point we figured the issue was roughly akin to the difference between the empty string and the null string -- where EOF is the null string, and 0 bytes of data is the empty string -- which you can't actually distinguish via read. I'm NOT saying this is exactly it, but I think it provides an analogy and a way to think about it. I think Plan 9 got it completely right. Being able to push a 0-byte write through the kernel is mighty handy. I got quite annoyed with Unix at various points over the years as I watched "optimizations" gobble up my attempts to get a 0 byte write through the kernel. Score one more for Plan 9 -- it lets you do what you want to do. I hope people enjoyed this discussion more than the up-arrow thread. thanks ron