5 ms·

A lot of the "design" of Unix was just happenstance, though. It didn't start from a tabula rasa, but mostly be reimplementing existing systems within a very con

by mhd 10y ago

A lot of the "design" of Unix was just happenstance, though. It didn't start from a tabula rasa, but mostly be reimplementing existing systems within a very constrained environment. And until you arrived at what's recognizably "Unix" for most people, there already was quite some evolution in place (At least V3, probably more V5). Just look at all the ad-hoc languages and semi-languages you've got there. Or the source code for the Bourne shell. roff formating. Then add BSD stuff on top of it (e.g. vi, sockets), the X window system, some more outside stuff (emacs, TeX) and you've got a bewildering plethora of icongruent systems way before Linux even splattered onto the scene. And I would say that McIlroys biggest invention (pipes) is the prime reason why this "mess" actually worked out, by providing a common way to tie these baroque and/or ad-hoc systems together. Unix never was a bright and shiny diamond of singular design beauty (there we'd have to look at language-based systems, IMHO, like Smalltalk, Lisp Machines, Mesa or Oberon). As for editors, well, with any application you end up having to trade simplicity for speed or power. For straight-forward text manipulation, "shelling" out is often a good alternative -- those tools might be arcane and baroque too (it's not like regular expressions are particular intuitive), but at least it's something you can use in other contexts, too. But when it comes to speedy and expedient movement through text and files, it's hard to beat a keyboard. And yes, I've used both acme and sam. Why would a shortcut be the epitome of mystery anyway? Sure, it's not evident on my screen/keyboard etc., but neither is having to use "==" for equality, '.*' for "match some characters" or, heck, these weird English words I'm now typing.

chubot 10y ago
I disagree. The main design idea behind Unix is composition. Uniformity enables composition, which means the overall system is smaller and doesn't collapse under its own weight. That means it survives, which we have observed empirically. Composition shows up in the following ways: 1) Everything is a file -- open() / close() / read() / write() are polymorphic, with ioctl() and others for the necessary hacks that don't fit the model. Devices are files; sockets are files; pipes are files; /proc is a file system and not a bunch of C APIs. Compare with Windows. This is not to say there's no cost to this uniformity. There is -- serialization and escaping bugs -- but in practice the benefit seems to have outweighed the cost. You can't underestimate composition, because without it your code collapses under its own weight.) 2) In addition to files composing, file systems compose. mount() is a way of composing a uniform namespace from disparate entities. (Not true under Windows) 3) Processes compose. You can do stuff like "sudo chroot ls ...". fork/exec allows one process to set state for another, without code changes to the child. (Also not true under Windows) 4) Language heterogeneity. Via the simple mechanism of the shebang line, shell can invoke awk/sed/Python/Perl/Ruby/JS in the same way. And the shell itself. (You could call this an instance of the Composite Design Pattern). Unix is certainly messy NOW, but that's because it is so widely used that everyone needed to add their own stuff to it (threads and shared libraries being very popular and arguably anti-Unix). You can try to make something "cleaner", but it will likely collapse under its own weight. There is no uniform model that encompasses all of computing. It's all little truths in specific situations. That's why there are so many little languages. I've had this argument before on HN: Lisp is not a better Unix. Lisp is solving a simpler problem; decades of experience have shown that. Unix is solving a harder problem, doing it in a somewhat simplistic and strained fashion, but it's the best we know how to do right now. Lisp or Smalltalk don't solve the same problem by any stretch of the imagination.
- pjmlp 10y ago
  UNIX stated getting messy the moment they added sockets and ioctl to it. I really don't know where this ideal model of UNIX lives. All your "not true under Windows" can be extended to all other OSes that aren't UNIX. Windows isn't the only non UNIX OS, although it appears to be like that to most HN eyes.
  - chubot 10y ago
    The way to have a system with an ideal model is to not use it... just publish a paper about it, and then lament that nobody gets it. Even though it hasn't been tested in many different situations and settings, you can still be smug about it. Whenever something hits the real world, people will add hacks to solve their immediate problems. That's just a property of software that has nothing to do with Unix.
    - pjmlp 10y ago
      So UNIX being a pile of hacks is ok, but other OSes having their quirks is bad design?
      - chubot 10y ago
        No, my claim is that Unix has good "bones", and Linux is all the hacks on top that make it work in the real world (more diverse hardware than Unix ever saw, diverse users, alternate models like Android and JVM, etc.) And that Linux needs some design leadership right now. When you have good bones, the hacks have something to rest on. The system still has some coherence, and doesn't degrade into a pile of mud. Linux is wading dangerously into that territory. When something is widely used, there is no option to not have hacks... you either have bad architecture and hacks, or good architecture and hacks. There was a thread here a few days ago discussing how NT is the same... it has good bones from Cutler, but then Microsoft had to layer all the compatibility hacks on top, for Windows 95 earlier. That's probably true to some extent. I guess I'm mainly saying that Windows is inferior in terms of system administration and scripting: shell scripts, fork/exec, shebang lines, the file system abstraction, etc. Threads and async I/O were not in the original Unix model, so it's perhaps not surprising if Windows does that better.

by mhd 10y ago

chubot 10y ago

I disagree. The main design idea behind Unix is composition. Uniformity enables composition, which means the overall system is smaller and doesn't collapse under its own weight. That means it survives, which we have observed empirically. Composition shows up in the following ways: 1) Everything is a file -- open() / close() / read() / write() are polymorphic, with ioctl() and others for the necessary hacks that don't fit the model. Devices are files; sockets are files; pipes are files; /proc is a file system and not a bunch of C APIs. Compare with Windows. This is not to say there's no cost to this uniformity. There is -- serialization and escaping bugs -- but in practice the benefit seems to have outweighed the cost. You can't underestimate composition, because without it your code collapses under its own weight.) 2) In addition to files composing, file systems compose. mount() is a way of composing a uniform namespace from disparate entities. (Not true under Windows) 3) Processes compose. You can do stuff like "sudo chroot ls ...". fork/exec allows one process to set state for another, without code changes to the child. (Also not true under Windows) 4) Language heterogeneity. Via the simple mechanism of the shebang line, shell can invoke awk/sed/Python/Perl/Ruby/JS in the same way. And the shell itself. (You could call this an instance of the Composite Design Pattern). Unix is certainly messy NOW, but that's because it is so widely used that everyone needed to add their own stuff to it (threads and shared libraries being very popular and arguably anti-Unix). You can try to make something "cleaner", but it will likely collapse under its own weight. There is no uniform model that encompasses all of computing. It's all little truths in specific situations. That's why there are so many little languages. I've had this argument before on HN: Lisp is not a better Unix. Lisp is solving a simpler problem; decades of experience have shown that. Unix is solving a harder problem, doing it in a somewhat simplistic and strained fashion, but it's the best we know how to do right now. Lisp or Smalltalk don't solve the same problem by any stretch of the imagination.

pjmlp 10y ago
UNIX stated getting messy the moment they added sockets and ioctl to it. I really don't know where this ideal model of UNIX lives. All your "not true under Windows" can be extended to all other OSes that aren't UNIX. Windows isn't the only non UNIX OS, although it appears to be like that to most HN eyes.
- chubot 10y ago
  The way to have a system with an ideal model is to not use it... just publish a paper about it, and then lament that nobody gets it. Even though it hasn't been tested in many different situations and settings, you can still be smug about it. Whenever something hits the real world, people will add hacks to solve their immediate problems. That's just a property of software that has nothing to do with Unix.
  - pjmlp 10y ago
    So UNIX being a pile of hacks is ok, but other OSes having their quirks is bad design?
    - chubot 10y ago
      No, my claim is that Unix has good "bones", and Linux is all the hacks on top that make it work in the real world (more diverse hardware than Unix ever saw, diverse users, alternate models like Android and JVM, etc.) And that Linux needs some design leadership right now. When you have good bones, the hacks have something to rest on. The system still has some coherence, and doesn't degrade into a pile of mud. Linux is wading dangerously into that territory. When something is widely used, there is no option to not have hacks... you either have bad architecture and hacks, or good architecture and hacks. There was a thread here a few days ago discussing how NT is the same... it has good bones from Cutler, but then Microsoft had to layer all the compatibility hacks on top, for Windows 95 earlier. That's probably true to some extent. I guess I'm mainly saying that Windows is inferior in terms of system administration and scripting: shell scripts, fork/exec, shebang lines, the file system abstraction, etc. Threads and async I/O were not in the original Unix model, so it's perhaps not surprising if Windows does that better.