Ten lines of code that changed my world

(pixelambacht.nl)

78 points | by dimonomid 4 hours ago

11 comments

  • dahart 2 hours ago
    The BASIC print+goto loop might have been my first ever program too (in the 80s) but one thing for sure for me: it was definitely not “Hello, World”. I and others filled the screen with any number of silly things, random words, jokes and juvenile phrases, whatever, but for some reason, “Hello, World!” was a C thing, and I remember seeing it for the first time in a C class in high school, and then much more often in college.

    I have memories of ‘poke’ as well. On the Atari 800 you could poke memory to change the keystroke repeat rate and delay before repeat started, so obviously we would turn down the delay to zero and turn up the repeat to max (it was maybe 60 characters per second), so anyone trying to type couldn’t hit the keys quickly enough to avoid repeating. You’d have to power-cycle the machine to fix it, so it was hilarious to 11 year old me.

    Similar to his description of ‘poke’, but different mechanism - using debug.com on an IBM PC jr to edit the Ultimate III save files, and give myself maximum money and lives.

    Good times!

    • codazoda 19 minutes ago
      I have been building BASIC32, a ROM BASIC like the ones I grew up with.

      The first one runs on an ESP32 that I plan to use as a watch. The software works, I just need to finish the 3D printed case.

      The second runs on an RP2350 connected to my living room TV via an HDMI cord.

      I have so much appreciation for these old machines I grew up with.

          BASIC32
          
          Ready.
    • mcherm 1 hour ago
      The reason that "Hello, World" is a C thing is that C is the source of the tradition around that phrase. In Kernighan and Richie's "The C Programming Language" printing "Hello, World" is the very first exercise.
    • dgacmu 1 hour ago
      Most definitely the juvenile phrases.

      I think my second BASIC program was the "guess a number" one -- that seemed really popular in intro basic programming things in the 80s also since it showed keyboard input and conditionals and was, uh, fun-adjacent.

    • andsoitis 50 minutes ago
      Concur. Us hackers who got started with BASIC had a more fun and creative ethos.
  • yboris 3 minutes ago
    Loved the The speed-up loop section. Smart move!
  • tptacek 38 minutes ago
    Hmm. What a great question.

        while(1) { fork(); } 
    
    Must have meant something to me, because it was in my Usenet sig. And then:

        exit(main(kfp->kargc, argv, environ));
    
    from FreeBSD crt0; kind of a big moment for me to realize there was more C code underneath main().

    Then:

        statements: /*E*/ | statement statements
    
    The moment Yacc clicked for me; that line was profound but a more accurate depiction of the moment was realizing that all you were doing with the parser generator was building a tree, and that's what the side effects of each production were for: returning and plugging in tree nodes.

    If there was a single line I could come up with for "double the size of the hash table when it fills up", that'd deserve a slot here.

    Then, of course (we get to cheat because assembly):

        jmp .call
        .pop: pop esi
        ...
        .call: call .pop
    
    The "delta offset" trick, which I believe came from x86 virus culture but was universal in 90s overflow exploits as a way to get position-independent references to strings and other memory things.

    For sure:

        void walk(node *n) { if(!n) return; walk(n->left); visit(n); walk(n->right); }
    
    I should figure out a way to fit a write-select(2) into a line because that's another "oh shit" moment for me.

    Similarly: when Vern Paxson explained to me that he'd implemented TCP reassembly by simply opening up a file and using "seek" to place incoming segments in the right position. I could probably golf that down to a line! But it would be an annoying line.

  • probably_wrong 2 hours ago
    I have been collecting small code snippets that would make for good tattoos and I have to say, some of these ones would probably make a good addition to the collection.

    I'm partially more in favor of "red" instead of "hotpink" for CSS, but that's just me.

    • apsurd 1 hour ago
      mine would be something like

          p { color: red; }
      
      as a teenager my mind was blown as I reloaded the page and there it was; text now in red. I did that!
    • thenthenthen 1 hour ago
      You have this one right?

      (){ :|:& };:

      • mattrighetti 1 hour ago
        Don’t forget the function name at the very beginning!

        :(){ :|:& };:

  • andsoitis 53 minutes ago
    Here are 3 lines that capture something profound about Lisp: code can manufacture code that manufactures code:

    ———————

    (defmacro twice (form)

      `(progn ,form ,form))
    
    (twice (print "Reality"))

    ———————

    twice doesn’t execute its argument twice. It rewrites the program itself before execution into:

    (progn

        (print "Reality") 
    
        (print "Reality"))
  • layer8 34 minutes ago
    > This tiny batch script allowed for a poor man’s `touch` on Windows, which I used extensively from Windows NT to Windows 7. I typed `touch filename.txt` in the Total Commander mini-shell to quickly generate new, empty files.

    This is funny to me, because I associate touch more with updating the timestamp of an existing file, and that script would miserably (destructively) be failing at that.

    • xp84 6 minutes ago
      yeah i get the utility for the 'making new file' use case, but aliasing this as touch if you're used to touch for both uses scares me!
  • throw34889 55 minutes ago
    For debugging CSS, I prefer something along the lines of:

        * {
          outline: 1px solid hotpink !important;
          outline-offset: -1px !important;
        }
    
    As in most cases the above snippet doesn't reflow content.

    Exercise to the reader is to turn the above into a javascript bookmarklet toggle, and to add support for shading margins and padding.

    • chias 40 minutes ago
      if you're using firefox, you can generally juts ctrl-click on the page. It'll draw outlines around every child element without reflowing.
  • ulfbert_inc 35 minutes ago
    Such a lovely article. Thanks for sharing.
  • beanaroo 21 minutes ago
    Another fun one for a bit of shenanigans:

      #define true ((rand()&15)!=15)
  • analog8374 58 minutes ago
    My first shipped code was an art thing. C64 Basic. Poke random characters to random locations on the screen. Random colors, screen and border too. On infinite goto loop. Radio Shack (IIRC) in the local mall used it on all their C64s.
  • irregularbowels 2 hours ago
    [dead]