6 ms·

Unix and Flow-Based Programming

49 points by nprincigalli 11y ago

SixSigma 11y ago
> Then Tannenbaum came out with his book and it didn’t really take off. > Then Torvalds open-sourced linux and that is what started to gain popularity. cough BSDi cough
- nickpsecurity 11y ago
  To support your point: https://web.archive.org/web/19990224090656/http://www.bsdi.com/company/ https://web.archive.org/web/19990224090656/http://www.bsdi.c... Seeing the list, now I'm sure which BSD that SCC likely used in their Sidewinder firewall. They modified it to have mandatory access controls to contain breaches of subsystems. This was before SELinux, etc. Never used BSDi, though, so can't say much about it except its users were getting pretty of mileage out of it given rep of products based on it. Least in appliances.
  - SixSigma 11y ago
    We used BSDi to launch an ISP in 1995, with 20 modems and 512kbps of bandwidth. I still have the Cdrom and we do hosting nowadays.
    - nickpsecurity 11y ago
      How much did it cost out of curiosity?
      - SixSigma 11y ago
        I really can't remember. I didn't order it myself.
teddyh 11y ago
> I was going to mention Unix “cat” but forgot. > Wildly simple - it takes at most one argument. That is asinine. Why would a program be called ‘cat’ if it can’t concatenate multiple files? Also, his “grash” program is seriously deficient in the handling of signals – it completely ignores the issue. There are many subtle issues with signals which have to be handled correctly when writing a shell: http://www.cons.org/cracauer/sigint.html http://www.cons.org/cracauer/sigint.html
- yarrel 11y ago
  cat takes as many files as you pass it, yes.
- epistasis 11y ago
  "cat" sounds like the abbreviation of "catenate" not "concatenate". Perhaps its possible that later versions of cat allowed more than one argument?
  - RadioactiveMan 11y ago
    Catenate means to connect things together[1], which implies it was named with multiple files in mind. [1] https://en.m.wiktionary.org/wiki/catenate https://en.m.wiktionary.org/wiki/catenate
    - epistasis 11y ago
      I'd think that it's chaining together the characters in the file, catenating a file to the screen. Wikipedia claims that the first version of Unix did a single file. https://en.wikipedia.org/wiki/Cat_(Unix)#History https://en.wikipedia.org/wiki/Cat_(Unix)#History Whereas "con"catenate means to link separate things together. These are minor distinctions, but if somebody is going to call things "asinine" they should at least get the pedantry correct.
      - RadioactiveMan 11y ago
        Good to know. Reading definitions of concatenate and catenate, I was confused about whether there actually was a difference or not. Edit: that wikipedia page makes it sound like the program it replaced was the one that prints a single file to the screen.
bitwize 11y ago
Well yeah, but that's not really how complex systems are developed anymore. Modern software development uses the object as the modular unit of granularity, not the process -- and APIs, perhaps augmented with message queues, for communication rather than pipes, sockets, and file descriptors. This is because it's much easier to statically reason about objects with well-defined APIs and they can be composed more flexibly with appropriate fabric: interacting locally or across process, user, or system boundaries. This model dates back at least as far as Smalltalk but what really caused it to take off was -- wait for it -- Windows COM. So modern development has moved on from the Unix philosophy and embraced the Windows philosophy.
- chubot 11y ago
  Uh, this is crazy wrong. Maybe in the desktop era objects were more important, but processes have come back with a vengeance now that everything is a distributed system. I'm not sure what you mean about objects being composed across system or process boundaries. Name a successful system where that's true. Who uses DCOM? Distributed objects failed. I occasionally see people trying to bring back this way of thinking (e.g. they want methods instead of RPCs and protobufs), but they have not succeeded, for fundamental reasons. In reality it's not either-or. You need both ways of thinking. Objects are static (they exist as an agreement between the compiler and programmer, and are usually thrown away at runtime); processes are dynamic. Many programmers that think only in terms of objects learn the hard way that their programs are brittle and inefficient. System operators think in terms of processes, and this way of thinking is essential for resilient systems. In addition, objects are losing importance in distributed systems because state in a single machine's memory is not very useful. In real distributed systems you need replicated/resilient state with varying consistency guarantees. An object doesn't help you with any of those things.

49 points by nprincigalli 11y ago

> Then Tannenbaum came out with his book and it didn’t really take off. > Then Torvalds open-sourced linux and that is what started to gain popularity. cough BSDi cough

nickpsecurity 11y ago
To support your point: https://web.archive.org/web/19990224090656/http://www.bsdi.com/company/ https://web.archive.org/web/19990224090656/http://www.bsdi.c... Seeing the list, now I'm sure which BSD that SCC likely used in their Sidewinder firewall. They modified it to have mandatory access controls to contain breaches of subsystems. This was before SELinux, etc. Never used BSDi, though, so can't say much about it except its users were getting pretty of mileage out of it given rep of products based on it. Least in appliances.
- SixSigma 11y ago
  We used BSDi to launch an ISP in 1995, with 20 modems and 512kbps of bandwidth. I still have the Cdrom and we do hosting nowadays.
  - nickpsecurity 11y ago
    How much did it cost out of curiosity?
    - SixSigma 11y ago
      I really can't remember. I didn't order it myself.

teddyh 11y ago

> I was going to mention Unix “cat” but forgot. > Wildly simple - it takes at most one argument. That is asinine. Why would a program be called ‘cat’ if it can’t concatenate multiple files? Also, his “grash” program is seriously deficient in the handling of signals – it completely ignores the issue. There are many subtle issues with signals which have to be handled correctly when writing a shell: http://www.cons.org/cracauer/sigint.html http://www.cons.org/cracauer/sigint.html

yarrel 11y ago
cat takes as many files as you pass it, yes.
epistasis 11y ago
"cat" sounds like the abbreviation of "catenate" not "concatenate". Perhaps its possible that later versions of cat allowed more than one argument?
- RadioactiveMan 11y ago
  Catenate means to connect things together[1], which implies it was named with multiple files in mind. [1] https://en.m.wiktionary.org/wiki/catenate https://en.m.wiktionary.org/wiki/catenate
  - epistasis 11y ago
    I'd think that it's chaining together the characters in the file, catenating a file to the screen. Wikipedia claims that the first version of Unix did a single file. https://en.wikipedia.org/wiki/Cat_(Unix)#History https://en.wikipedia.org/wiki/Cat_(Unix)#History Whereas "con"catenate means to link separate things together. These are minor distinctions, but if somebody is going to call things "asinine" they should at least get the pedantry correct.
    - RadioactiveMan 11y ago
      Good to know. Reading definitions of concatenate and catenate, I was confused about whether there actually was a difference or not. Edit: that wikipedia page makes it sound like the program it replaced was the one that prints a single file to the screen.

bitwize 11y ago

Well yeah, but that's not really how complex systems are developed anymore. Modern software development uses the object as the modular unit of granularity, not the process -- and APIs, perhaps augmented with message queues, for communication rather than pipes, sockets, and file descriptors. This is because it's much easier to statically reason about objects with well-defined APIs and they can be composed more flexibly with appropriate fabric: interacting locally or across process, user, or system boundaries. This model dates back at least as far as Smalltalk but what really caused it to take off was -- wait for it -- Windows COM. So modern development has moved on from the Unix philosophy and embraced the Windows philosophy.

chubot 11y ago
Uh, this is crazy wrong. Maybe in the desktop era objects were more important, but processes have come back with a vengeance now that everything is a distributed system. I'm not sure what you mean about objects being composed across system or process boundaries. Name a successful system where that's true. Who uses DCOM? Distributed objects failed. I occasionally see people trying to bring back this way of thinking (e.g. they want methods instead of RPCs and protobufs), but they have not succeeded, for fundamental reasons. In reality it's not either-or. You need both ways of thinking. Objects are static (they exist as an agreement between the compiler and programmer, and are usually thrown away at runtime); processes are dynamic. Many programmers that think only in terms of objects learn the hard way that their programs are brittle and inefficient. System operators think in terms of processes, and this way of thinking is essential for resilient systems. In addition, objects are losing importance in distributed systems because state in a single machine's memory is not very useful. In real distributed systems you need replicated/resilient state with varying consistency guarantees. An object doesn't help you with any of those things.