peter@sugar.UUCP (09/11/87)
In article <130@stb.UUCP>, michael@stb.UUCP (Michael) writes: > Okay, lets look at unix pipes. I assume you mean Named Fifo's (pipe files > in file space vs. pipe(2) sys call). Yeh, that's what I mean. > #1. 4K buffer--after that, you wait until someone else reads it. I don't see this as a problem. Large writes will have to wait. A lot of small writes will have to wait. This will happen anyway... and 4K seems a reasonable number. It works for me. > #2. The system I have makes the writer wait until a reader shows up. You're right. Well, I still think it desirable that you be able to write a small packet to a pipe and go away. > #3. Both multiple readers and writers are allowed (remember: The dup() call > will work for anything in unix, and fork implicitly dups every file > descriptor). Yes, especially multiple writers. > #4. You cannot reopen without losing data. Probably right again... > Which system are you thinkin of? 4.3? (I'm using sys3). If I understand > correctly, that system does not guarantee any atomicy of writes to pipes. System V. > >> Besides, I like P:, which can have multiple readers. > > > >I find it hard to fathom the use of multiple readers to a single pipe. Perhaps > >you can describe an application you've used this feature for. > > Look at the "tee" command in unix. P: will send identical copies of data to > a file, such as a CON: window, or another pipe (to another program), so > one program's output will go to two destination programs. That's interesting. I'm not sure how to make it consistent. What happens when a reader opens a pipe after another reader has already read some data? I was thinking in terms of the way UNIX handles multiple readers, where each gets part of the data. > >> : Copy protection? Just say Pirate! (if its worth pirating) > > > >How are people supposed to take you seriously if you say things like this? > > Gee, I suppose very. Seriously, I am strongly opposed to copy protection and > "machine takeovers" So am I. Piracy isn't an appropriate response, just don't buy it in the first place. There is a difference between free enterprise and theft. -- -- Peter da Silva `-_-' ...!seismo!soma!uhnix1!sugar!peter -- 'U` <-- Public domain wolf.