8 ms·

Decoded: GNU Coreutils

256 points by bshanks 7y ago

AceJohnny2 7y ago
Huh, I'd never heard of FTS before, the functions used by Coreutils to traverse the filesystem: http://man7.org/linux/man-pages/man3/fts.3.html http://man7.org/linux/man-pages/man3/fts.3.html
- woodruffw 7y ago
  FWIW, the POSIX equivalents are `ftw` and `nftw`[1]. POSIX 2008 deprecates `ftw`. [1]: https://pubs.opengroup.org/onlinepubs/9699919799//functions/nftw.html https://pubs.opengroup.org/onlinepubs/9699919799//functions/...
  - wahern 7y ago
    ftw/nftw is a crap interface as it relies on C callbacks and isn't re-entrant.[1] Android/Bionic, Darwin/macOS, DragonflyBSD, FreeBSD, glibc, musl libc, OpenBSD, NetBSD, and even Solaris all support the FTS API.[2] Of the extant Unix environments only AIX and QNX seems to lack it. HP-UX doesn't seem to support it, either, but I don't count HP-UX as extant. In any event it's trivial to copy an FTS implementation from a BSD. I'm a strong advocate for adherence to POSIX, but in this case there's significant benefit from using FTS and very little, if any, cost. [1] FTS uses a C callback for its comparator, which can be a headache but not nearly to the same extent as it is with nftw. [2] It's originally from BSD Reno. It was adopted by glibc, which in turn has forced commercial vendors like Solaris to support it as they're chasing Linux/glibc API compatibility. I would expect AIX to add it eventually.
    - woodruffw 7y ago
      Ah, linux-man bites again: the Linux versions of `nftw` and `ftw` claim to be re-entrant, so I assumed that POSIX specified them as such. Looks like I was wrong about that.
      - Anthony-G 7y ago
        Red Hat-based distributions include POSIX man pages out of the box. $ whatis ftw ftw (3) - file tree walk ftw (3p) - traverse (walk) a file tree Run `man 3p ftw` to read the POSIX version. On Ubuntu systems, the following packages can be installed to provide the POSIX man pages: manpages-posix manpages-posix-dev
    - rwmj 7y ago
      Annoyingly FTS was completely broken on 64 bit platforms in glibc before 2016. This still affects some enterprise systems (RHEL 7 in my case). Coreutils uses gnulib to replace glibc FTS with a working version on these systems.
nn3 7y ago
that's fairly cool. Wish such sites were available for more open source packages. Always wanted to know the algorithms used in sort. So ls has more source lines than sort? Funny, but a bit depressing too.
- Lt_Riza_Hawkeye 7y ago
  ls is kind of complicated, has a billion flags, and has to print pretty so it has to do some ioctls to get the terminal width and such, then column things out nicely so they don't overflow. Glad I'm not implementing ls from scratch.
  - michaelmior 7y ago
    exa[0] dubs itself a "modern" ls written in Rust. Interesting to compare. Still over 6,000 lines not including comments. [0] https://github.com/ogham/exa https://github.com/ogham/exa
cat199 7y ago
Or, just browse the originals: https://www.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src https://www.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src https://www.tuhs.org/cgi-bin/utree.pl?file=4.3BSD/usr/src https://www.tuhs.org/cgi-bin/utree.pl?file=4.3BSD/usr/src and some of their current decedents: https://svnweb.freebsd.org/ https://svnweb.freebsd.org/ http://cvsweb.openbsd.org/cgi-bin/cvsweb/ http://cvsweb.openbsd.org/cgi-bin/cvsweb/ http://cvsweb.netbsd.org/bsdweb.cgi/src/?only_with_tag=MAIN http://cvsweb.netbsd.org/bsdweb.cgi/src/?only_with_tag=MAIN https://gitweb.dragonflybsd.org/dragonfly.git https://gitweb.dragonflybsd.org/dragonfly.git conveniently all in one source tree, self hosting, and buildable with a single command. it is almost as if they were designed as part of a single coherent operating system along with the very C language itself.. as discussed previously, typically with more intelligible sources: https://news.ycombinator.com/item?id=14542938 https://news.ycombinator.com/item?id=14542938 and usually with better man pages (https://www.freebsd.org/cgi/man.cgi https://www.freebsd.org/cgi/man.cgi) unix came first. gnu and posix came later. the unix way is the standard, not posix, and not gnu. from stallman himself (https://stallman.org/articles/posix.html https://stallman.org/articles/posix.html): " It seemed to me that nobody would ever say "IEEEIX", since the pronunciation would sound like a shriek of terror; rather, everyone would call it "Unix". That would have boosted AT&T, the GNU Project's rival, an outcome I did not want. So I looked for another name, but nothing natural suggested itself to me. So I put the initials of "Portable Operating System" together with the same suffix "ix", and came up with "POSIX". It sounded good and I saw no reason not to use it, so I suggested it. Although it was just barely in time, the committee adopted it. " so, as can be seen, posix is RMS's way of keeping people from calling unix unix, and as a result today, now that AT&T Unix is nearly dead, people lose track of the fact that BSD is Unix, and don't know what Unix actually is, and are forced to 'decode' the sometimes deliberately less clear cloned sources not knowing to look at the simpler original.
- AceJohnny2 7y ago
  I think you missed the point of the website. It's not about the source code itself, but providing a higher-level overview of the utilities' architecture.
  - 7y ago
enriquto 7y ago
this is very cool. Yet GNU utils have so many options that the interesting bits are difficult to find. The same display but for openbsd utils would be still more enlightening.
p0cc 7y ago
This is amazing. The author needs a donate button!
OJFord 7y ago
Oh, this is great! And it's one piece of something I've been looking for (so hopefully a good comment section to ask for more): a book on how (GNU/)Linux 'works'. i.e. I'm not interested in a book of commands or cheat sheets, I can use `man` and SO, Arch wiki, etc. for that when needed. I think part of the problem is that I don't know what I don't know - but I discovered namespaces (`/proc/<pid>/ns/<type>`) recently and don't know much about it but thought it was interesting, and managed to use it to do what I needed to overcome a problem I was having with `ip netns`. A similar 'aha' was with inodes a while ago. So, any recommendations for a book on 'how Linux works'? I think it's a gap in my understanding (academically EE/CS - hardware, up to OS but not Linux-specific, theoretical CS; professionally software, 'using' Linux). Best candidate I've found is Brian Ward's 'How Linux Works: what every superuser should know'.
ben165 7y ago
Nice project. Just looked for the source code of "yes" (https://github.com/coreutils/coreutils/blob/master/src/yes.c https://github.com/coreutils/coreutils/blob/master/src/yes.c), cause it seems to be the easiest code to understand. I didn't get it. Damn. Looks still complicated.
- yjftsjthsd-h 7y ago
  Yeah, `yes` ended up complex in order to get better performance; if you want something simpler, maybe try https://www.maizure.org/projects/decoded-gnu-coreutils/env.html https://www.maizure.org/projects/decoded-gnu-coreutils/env.h... ?
AstroJetson 7y ago
Interesting project, this would make a good teaching tool for people interested in more operating system interaction. On the website it would be nice if you had a way to flag which ones were fully annotated. But I like the main page design. The block graphics on the flow is very helpful. You've done some very nice work here.
- SamuelAdams 7y ago
  Agreed, this would be very beneficial to students and people learning C.
  - saagarjha 7y ago
    I have used the source code for Plan 9's core utilities as a teaching aid for students learning the basics of C and operating systems to great effect. I have found GNU's tools to contain a lot of "cruft" to make them run fast, which is not necessarily conducive for those who are not familiar to why they work.
    - klez 7y ago
      Yeah, plan 9 was my second thought when I saw this. The first one was suckless' core.
      - saagarjha 7y ago
        suckless seems like a spiritual successor to Plan 9 (albeit POSIX), to the point that it uses some of the same constructs, so I’m not surprised that you thought of it.
    - pantalaimon 7y ago
      Busybox and Toybox also contain pretty simple and easy to follow implementations.
      - AstroJetson 7y ago
Tepix 7y ago
Super interesting. I had a brief look at "head" and "df" and the flows seem to be complete. The flow for "tr" is not completely right given that the second parameter ("string2") is optional with certain options. The text for "yes" mentions how it fills a buffer with multiple copies of the string to achieve its very high performance. Nice!
- yodon 7y ago
  Reminds me of a time at a large animation studio where I was working on performance issues with the in-house asset management system. The asset management tool was fully commandline based, no GUI. An artist showed me what was involved in committing their scene: launch the command, type yes, hit return, wait about 30 seconds, type yes, hit return, repeat. I piped yes to stdin and it ran for 47 hours. If you need a performance-optimized version of "yes" there are probably other aspects of your architecture you should look at first.
  - masklinn 7y ago
    yes(1) takes a custom "expletive", so in the performance context it's usually used for flood filling in situations where e.g. /dev/zero or /dev/urandom are not appropriate sources for some reason.
    - saagarjha 7y ago
      yes outputs newlines, though, which makes it somewhat annoying to use for flood filling in practice.
ketanhwr 7y ago
This guy has some really nice articles, but I'm unavailable to find any link to his RSS feed. Any help?
ape4 7y ago
Rather than a flow chart, etc. It would better to convert the utilities to simple C with no error handling or optimization. So `cat` would be about 5 lines. No mmap() or fancy stuff.
- saagarjha 7y ago
  Many older operating systems do a pretty decent job at this: I would suggest taking a look at those. (Alternatively, if you're looking for something that's still modern, BSD usually cares less about optimization than GNU does.)
- zyztem 7y ago
  You might find source of Xv6 - educational version of unix - useful. Here is their implementation of cat, all 44 lines of it: https://github.com/mit-pdos/xv6-public/blob/master/cat.c https://github.com/mit-pdos/xv6-public/blob/master/cat.c
NikkiA 7y ago
I never noticed `runcon` before, it and `chcon` seem decidedly out of place being in core-utils, being that they're a) linux specific, b) SElinux specific.
reuben_scratton 7y ago
I'm not particularly interested in coreutils per se but this is a super-interesting way to look at any piece of software. I just _love_ the block diagrams... why can't source code look like this? Great work!
- stormbrew 7y ago
  There are languages that model code like this. Using one for a while will likely teach you why. If you think "spaghetti" is an apt description for text code, wait until you see flow based code that's evolved in place for a while.
  - jancsika 7y ago
    In the best of those languages the user is getting input and output through the diagram in realtime. Also, syntax errors are either removed completely or converted into runtime errors. These features allow the user to iterate rapidly through the development process to create a prototype, perhaps even gaining an average 100x development-time increase over using a compiled text-based language. The spaghetti is evidence of that-- the user moved so quickly that they were able to hold the relevant abstractions in their short term memory to produce the final write-only diagram. And at least in my experience, the final write-only diagrams tend to work to produce the desired output, even if they were written a decade ago. In fact if there were a button users could push to "abstractify" some pre-spaghetti sub-diagram I believe that would negatively impact the language. The point is that when you've got mental model of all inputs and outputs within a single page visual cheat sheet, you can instantly connect any input to any output to take the next step in the development process. For certain domains like audio synthesis the fact that the user can leverage the diagram-based system to get any output at all is worth the seemingly prohibitive price of write-only programming.
  - patrick5415 7y ago
    Labview is one of these languages, which I’ve used for the last 5 years. It’s the only tool I use daily that makes me want to blow my brains out. I think diagrams like these are really useful as high level visualizations, but fail miserably as a low level implementation. It’s my opinion that one of the things that turns visual code into spaghetti is that refactoring is difficult, because the code grows in 2d, as opposed to 1d (I don’t count line length). It’s sort of like if you could have infinitely many columns of concurrently executing code in text a based function, where any line in a given column can be connected to any line in a different column. I think what could be useful is a hybrid model, where you have something like text based modules whose communication is orchestrated by a visual diagram. For what it’s worth, Simulink can be used like this to some extent(e.g., hooking S-functions together) and I find it orders of magnitude more pleasant than labview.
xerxex 7y ago
This is fantastic work!
ausjke 7y ago
the diagram is really nice,is it done by dia? I use dia once a while, and wish freeplane could draw arrows between its nodes as freeplane is easier to add child nodes.
myroon5 7y ago
I've been trying to contribute additional flags for some coreutils commands, but I've been having trouble building on macOS. Should I use a certain VM or container instead? Does anyone have a link to instructions for building on a mac?
- mattl 7y ago
  Do you have a modern GCC installed?
  - myroon5 7y ago
    $ gcc -v Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk/usr/include/c++/4.2.1 Apple LLVM version 10.0.1 (clang-1001.0.46.4) Target: x86_64-apple-darwin18.6.0 Thread model: posix InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
    - efficax 7y ago
      I would not at all be suprised to learn that GNU coreutils does not build with clang/llvm. Try installing a real GNU C compiler with homebrew (brew install gcc)
tinktank 7y ago
Are you doing this by manual inspection or in some semi-automated or automated way? In any case, very nice work.
theqoo 7y ago
It is true archeology.
hermitdev 7y ago
This is probably going to be an unpopular opinion, I dont agree with the criticism of the use of goto. I know, I know, the classic "goto Considered Harmful". And, yes, it can be abused just like every other programming construct. I see 2 generally good use cases for goto: 1) error handling to cleanup in failure in C (in C++ RIAA constructs ahould be used instead) 2) exitting nested loops, instead of a flag and a break. I've also seen C++ code use do while loops with while(false) so that they could use "break" to exit the non loop. Its very confusing and non obvious, because you see the do, and thus expect a loop. Meanwhile (the absurdly long function) has the while(false) on a separate screen, not making it clear that the code doesn't actually loop. Just use the goto. It's clearer and omits the abuse of a looping primitive (that doesn't actually loop). Yes, goto can be abused, so can many other statements. Sorry, /rant
bshanks 7y ago
If you like this, the author posts a number of other 'Decoded' episodes: https://www.maizure.org/projects/ https://www.maizure.org/projects/

256 points by bshanks 7y ago

Huh, I'd never heard of FTS before, the functions used by Coreutils to traverse the filesystem: http://man7.org/linux/man-pages/man3/fts.3.html http://man7.org/linux/man-pages/man3/fts.3.html

woodruffw 7y ago
FWIW, the POSIX equivalents are `ftw` and `nftw`[1]. POSIX 2008 deprecates `ftw`. [1]: https://pubs.opengroup.org/onlinepubs/9699919799//functions/nftw.html https://pubs.opengroup.org/onlinepubs/9699919799//functions/...
- wahern 7y ago
  ftw/nftw is a crap interface as it relies on C callbacks and isn't re-entrant.[1] Android/Bionic, Darwin/macOS, DragonflyBSD, FreeBSD, glibc, musl libc, OpenBSD, NetBSD, and even Solaris all support the FTS API.[2] Of the extant Unix environments only AIX and QNX seems to lack it. HP-UX doesn't seem to support it, either, but I don't count HP-UX as extant. In any event it's trivial to copy an FTS implementation from a BSD. I'm a strong advocate for adherence to POSIX, but in this case there's significant benefit from using FTS and very little, if any, cost. [1] FTS uses a C callback for its comparator, which can be a headache but not nearly to the same extent as it is with nftw. [2] It's originally from BSD Reno. It was adopted by glibc, which in turn has forced commercial vendors like Solaris to support it as they're chasing Linux/glibc API compatibility. I would expect AIX to add it eventually.
  - woodruffw 7y ago
    Ah, linux-man bites again: the Linux versions of `nftw` and `ftw` claim to be re-entrant, so I assumed that POSIX specified them as such. Looks like I was wrong about that.
    - Anthony-G 7y ago
      Red Hat-based distributions include POSIX man pages out of the box. $ whatis ftw ftw (3) - file tree walk ftw (3p) - traverse (walk) a file tree Run `man 3p ftw` to read the POSIX version. On Ubuntu systems, the following packages can be installed to provide the POSIX man pages: manpages-posix manpages-posix-dev
  - rwmj 7y ago
    Annoyingly FTS was completely broken on 64 bit platforms in glibc before 2016. This still affects some enterprise systems (RHEL 7 in my case). Coreutils uses gnulib to replace glibc FTS with a working version on these systems.

nn3 7y ago

that's fairly cool. Wish such sites were available for more open source packages. Always wanted to know the algorithms used in sort. So ls has more source lines than sort? Funny, but a bit depressing too.

Lt_Riza_Hawkeye 7y ago
ls is kind of complicated, has a billion flags, and has to print pretty so it has to do some ioctls to get the terminal width and such, then column things out nicely so they don't overflow. Glad I'm not implementing ls from scratch.
- michaelmior 7y ago
  exa[0] dubs itself a "modern" ls written in Rust. Interesting to compare. Still over 6,000 lines not including comments. [0] https://github.com/ogham/exa https://github.com/ogham/exa

cat199 7y ago

Or, just browse the originals: https://www.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src https://www.tuhs.org/cgi-bin/utree.pl?file=V7/usr/src https://www.tuhs.org/cgi-bin/utree.pl?file=4.3BSD/usr/src https://www.tuhs.org/cgi-bin/utree.pl?file=4.3BSD/usr/src and some of their current decedents: https://svnweb.freebsd.org/ https://svnweb.freebsd.org/ http://cvsweb.openbsd.org/cgi-bin/cvsweb/ http://cvsweb.openbsd.org/cgi-bin/cvsweb/ http://cvsweb.netbsd.org/bsdweb.cgi/src/?only_with_tag=MAIN http://cvsweb.netbsd.org/bsdweb.cgi/src/?only_with_tag=MAIN https://gitweb.dragonflybsd.org/dragonfly.git https://gitweb.dragonflybsd.org/dragonfly.git conveniently all in one source tree, self hosting, and buildable with a single command. it is almost as if they were designed as part of a single coherent operating system along with the very C language itself.. as discussed previously, typically with more intelligible sources: https://news.ycombinator.com/item?id=14542938 https://news.ycombinator.com/item?id=14542938 and usually with better man pages (https://www.freebsd.org/cgi/man.cgi https://www.freebsd.org/cgi/man.cgi) unix came first. gnu and posix came later. the unix way is the standard, not posix, and not gnu. from stallman himself (https://stallman.org/articles/posix.html https://stallman.org/articles/posix.html): " It seemed to me that nobody would ever say "IEEEIX", since the pronunciation would sound like a shriek of terror; rather, everyone would call it "Unix". That would have boosted AT&T, the GNU Project's rival, an outcome I did not want. So I looked for another name, but nothing natural suggested itself to me. So I put the initials of "Portable Operating System" together with the same suffix "ix", and came up with "POSIX". It sounded good and I saw no reason not to use it, so I suggested it. Although it was just barely in time, the committee adopted it. " so, as can be seen, posix is RMS's way of keeping people from calling unix unix, and as a result today, now that AT&T Unix is nearly dead, people lose track of the fact that BSD is Unix, and don't know what Unix actually is, and are forced to 'decode' the sometimes deliberately less clear cloned sources not knowing to look at the simpler original.

AceJohnny2 7y ago
I think you missed the point of the website. It's not about the source code itself, but providing a higher-level overview of the utilities' architecture.
- 7y ago

enriquto 7y ago

this is very cool. Yet GNU utils have so many options that the interesting bits are difficult to find. The same display but for openbsd utils would be still more enlightening.

p0cc 7y ago

This is amazing. The author needs a donate button!

OJFord 7y ago

Oh, this is great! And it's one piece of something I've been looking for (so hopefully a good comment section to ask for more): a book on how (GNU/)Linux 'works'. i.e. I'm not interested in a book of commands or cheat sheets, I can use `man` and SO, Arch wiki, etc. for that when needed. I think part of the problem is that I don't know what I don't know - but I discovered namespaces (`/proc/<pid>/ns/<type>`) recently and don't know much about it but thought it was interesting, and managed to use it to do what I needed to overcome a problem I was having with `ip netns`. A similar 'aha' was with inodes a while ago. So, any recommendations for a book on 'how Linux works'? I think it's a gap in my understanding (academically EE/CS - hardware, up to OS but not Linux-specific, theoretical CS; professionally software, 'using' Linux). Best candidate I've found is Brian Ward's 'How Linux Works: what every superuser should know'.

ben165 7y ago

Nice project. Just looked for the source code of "yes" (https://github.com/coreutils/coreutils/blob/master/src/yes.c https://github.com/coreutils/coreutils/blob/master/src/yes.c), cause it seems to be the easiest code to understand. I didn't get it. Damn. Looks still complicated.

yjftsjthsd-h 7y ago
Yeah, `yes` ended up complex in order to get better performance; if you want something simpler, maybe try https://www.maizure.org/projects/decoded-gnu-coreutils/env.html https://www.maizure.org/projects/decoded-gnu-coreutils/env.h... ?

AstroJetson 7y ago

Interesting project, this would make a good teaching tool for people interested in more operating system interaction. On the website it would be nice if you had a way to flag which ones were fully annotated. But I like the main page design. The block graphics on the flow is very helpful. You've done some very nice work here.

SamuelAdams 7y ago
Agreed, this would be very beneficial to students and people learning C.
- saagarjha 7y ago
  I have used the source code for Plan 9's core utilities as a teaching aid for students learning the basics of C and operating systems to great effect. I have found GNU's tools to contain a lot of "cruft" to make them run fast, which is not necessarily conducive for those who are not familiar to why they work.
  - klez 7y ago
    Yeah, plan 9 was my second thought when I saw this. The first one was suckless' core.
    - saagarjha 7y ago
      suckless seems like a spiritual successor to Plan 9 (albeit POSIX), to the point that it uses some of the same constructs, so I’m not surprised that you thought of it.
  - pantalaimon 7y ago
    Busybox and Toybox also contain pretty simple and easy to follow implementations.
    - AstroJetson 7y ago

Tepix 7y ago

Super interesting. I had a brief look at "head" and "df" and the flows seem to be complete. The flow for "tr" is not completely right given that the second parameter ("string2") is optional with certain options. The text for "yes" mentions how it fills a buffer with multiple copies of the string to achieve its very high performance. Nice!

yodon 7y ago
Reminds me of a time at a large animation studio where I was working on performance issues with the in-house asset management system. The asset management tool was fully commandline based, no GUI. An artist showed me what was involved in committing their scene: launch the command, type yes, hit return, wait about 30 seconds, type yes, hit return, repeat. I piped yes to stdin and it ran for 47 hours. If you need a performance-optimized version of "yes" there are probably other aspects of your architecture you should look at first.
- masklinn 7y ago
  yes(1) takes a custom "expletive", so in the performance context it's usually used for flood filling in situations where e.g. /dev/zero or /dev/urandom are not appropriate sources for some reason.
  - saagarjha 7y ago
    yes outputs newlines, though, which makes it somewhat annoying to use for flood filling in practice.

ketanhwr 7y ago

This guy has some really nice articles, but I'm unavailable to find any link to his RSS feed. Any help?

ape4 7y ago

Rather than a flow chart, etc. It would better to convert the utilities to simple C with no error handling or optimization. So `cat` would be about 5 lines. No mmap() or fancy stuff.

saagarjha 7y ago
Many older operating systems do a pretty decent job at this: I would suggest taking a look at those. (Alternatively, if you're looking for something that's still modern, BSD usually cares less about optimization than GNU does.)
zyztem 7y ago
You might find source of Xv6 - educational version of unix - useful. Here is their implementation of cat, all 44 lines of it: https://github.com/mit-pdos/xv6-public/blob/master/cat.c https://github.com/mit-pdos/xv6-public/blob/master/cat.c

NikkiA 7y ago

I never noticed `runcon` before, it and `chcon` seem decidedly out of place being in core-utils, being that they're a) linux specific, b) SElinux specific.

reuben_scratton 7y ago

I'm not particularly interested in coreutils per se but this is a super-interesting way to look at any piece of software. I just _love_ the block diagrams... why can't source code look like this? Great work!

stormbrew 7y ago
There are languages that model code like this. Using one for a while will likely teach you why. If you think "spaghetti" is an apt description for text code, wait until you see flow based code that's evolved in place for a while.
- jancsika 7y ago
  In the best of those languages the user is getting input and output through the diagram in realtime. Also, syntax errors are either removed completely or converted into runtime errors. These features allow the user to iterate rapidly through the development process to create a prototype, perhaps even gaining an average 100x development-time increase over using a compiled text-based language. The spaghetti is evidence of that-- the user moved so quickly that they were able to hold the relevant abstractions in their short term memory to produce the final write-only diagram. And at least in my experience, the final write-only diagrams tend to work to produce the desired output, even if they were written a decade ago. In fact if there were a button users could push to "abstractify" some pre-spaghetti sub-diagram I believe that would negatively impact the language. The point is that when you've got mental model of all inputs and outputs within a single page visual cheat sheet, you can instantly connect any input to any output to take the next step in the development process. For certain domains like audio synthesis the fact that the user can leverage the diagram-based system to get any output at all is worth the seemingly prohibitive price of write-only programming.
- patrick5415 7y ago
  Labview is one of these languages, which I’ve used for the last 5 years. It’s the only tool I use daily that makes me want to blow my brains out. I think diagrams like these are really useful as high level visualizations, but fail miserably as a low level implementation. It’s my opinion that one of the things that turns visual code into spaghetti is that refactoring is difficult, because the code grows in 2d, as opposed to 1d (I don’t count line length). It’s sort of like if you could have infinitely many columns of concurrently executing code in text a based function, where any line in a given column can be connected to any line in a different column. I think what could be useful is a hybrid model, where you have something like text based modules whose communication is orchestrated by a visual diagram. For what it’s worth, Simulink can be used like this to some extent(e.g., hooking S-functions together) and I find it orders of magnitude more pleasant than labview.

xerxex 7y ago

This is fantastic work!

ausjke 7y ago

the diagram is really nice,is it done by dia? I use dia once a while, and wish freeplane could draw arrows between its nodes as freeplane is easier to add child nodes.

myroon5 7y ago

I've been trying to contribute additional flags for some coreutils commands, but I've been having trouble building on macOS. Should I use a certain VM or container instead? Does anyone have a link to instructions for building on a mac?

mattl 7y ago
Do you have a modern GCC installed?
- myroon5 7y ago
  $ gcc -v Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk/usr/include/c++/4.2.1 Apple LLVM version 10.0.1 (clang-1001.0.46.4) Target: x86_64-apple-darwin18.6.0 Thread model: posix InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
  - efficax 7y ago
    I would not at all be suprised to learn that GNU coreutils does not build with clang/llvm. Try installing a real GNU C compiler with homebrew (brew install gcc)

tinktank 7y ago

Are you doing this by manual inspection or in some semi-automated or automated way? In any case, very nice work.

theqoo 7y ago

It is true archeology.

hermitdev 7y ago

This is probably going to be an unpopular opinion, I dont agree with the criticism of the use of goto. I know, I know, the classic "goto Considered Harmful". And, yes, it can be abused just like every other programming construct. I see 2 generally good use cases for goto: 1) error handling to cleanup in failure in C (in C++ RIAA constructs ahould be used instead) 2) exitting nested loops, instead of a flag and a break. I've also seen C++ code use do while loops with while(false) so that they could use "break" to exit the non loop. Its very confusing and non obvious, because you see the do, and thus expect a loop. Meanwhile (the absurdly long function) has the while(false) on a separate screen, not making it clear that the code doesn't actually loop. Just use the goto. It's clearer and omits the abuse of a looping primitive (that doesn't actually loop). Yes, goto can be abused, so can many other statements. Sorry, /rant

bshanks 7y ago

If you like this, the author posts a number of other 'Decoded' episodes: https://www.maizure.org/projects/ https://www.maizure.org/projects/