HN user
Since the rules are entirely reconstructed, I have to say I'm a bit skeptical of a game where a central point is keeping a count of moves up to 150. It seems too unpractical for a casual game.
Are there other known ancient games that work like this?
Yeah, I don't know about the author, but my brain spatial memory is very much tied to Euclidean geometry. The holonomy effect (view is rotated when coming back to the same point) in particular is very disorienting.
It's cool, but I would never use this for real.
I'd say not much: you update the channel, run nixos-rebuild switch, fix all the warnings/errors due to renamed/changed options until it succeeds and you're done. If you have a database like postgres you may have to do a schema upgrade manually, since the default version is updated every 4/5 releases or so.
It's very rare to find something that prevents you from directly updating. Nixpkgs tries very hard to no require new Nix features, so it evaluates with even Nix versions from a decade ago. Also, NixOS options and packages are frequently changed, but the automatic migrations (mkChangedOptionModule, mkRenamedOptionModule, alias, etc.) are never removed in practice.
Since the binary cache has never been cleared since its creation (2002?), it should actually be easy to install a super old NixOS release and upgrading it to the latest to see what happens.
By the way, there are LTS versions of NixOS, just not officially supported. See https://docs.ctrl-os.com/.
No they can't. They obviously know the IP addresses, but that's not terribly useful since everything is behind a cloudflare proxy nowadays. The server hostname may provide some more information, if the server doesn't support ECH [1], but the full URL is encrypted.
https://en.wikipedia.org/wiki/Server_Name_Indication#Encrypt...
they still see the URL so they can get the content if they want it
That's incorrect, a MitM can only reveal the server hostname by inspecting the SNI during the TLS handshake, but the HTTP request, including the URL and headers, is encrypted.
I just do this for the IP ranges of Amazon, OpenAI, Huawei and other companies that run these insane crawlers: it's 100% effective and it doesn't annoy real users with a captcha or some PoW thing. There's simply no reason for them to reach my homeserver other than to scrape the hell out of it.
It's the devops team can manage a measly 87% uptime [1] you're talking about, you can do a lot better on your homeserver.
The breeding blanket is entirely contained inside a vacuum vessel, so there isn't any oxygen to react with. Also, the are many blanket designs, but the lithium is never present in its elemental form (precisely because it would be very reactive), but in a stable chemical bond with some neutron multiplier (like lithium-lead alloys or beryllium ceramics). In some design the lithium is even immersed in the coolant itself, which is high pressure helium, so it's not going to ignite in any reasonable way.
How is that done if not using CSMA/CD (or something very similar at least)?
AFAIK, WiFi has always been doing CSMA/CA and starting with the 802.11ax standard also OFDMA. See https://en.wikipedia.org/wiki/Hidden_node_problem#Background
Previous discussions:
https://news.ycombinator.com/item?id=14986324 (2017)
https://news.ycombinator.com/item?id=20167686 (2019)
So, I did a bit of research and I wasn't going crazy: there are apparently two competing definitions of "elementary" in use [1]:
the class of functions [...] is what I would call exponential-logarithmic functions or EL functions; that is, they are the functions that can be expressed using some finite combination of constant functions, the identity function, exp, log, composition, and arithmetic operations (+−×÷). Some authors call this class of functions elementary functions, but that term is now more commonly used in a different sense, which includes algebraic functions.
Evidently my professor was in the exponential-logarithmic camp.
I guess you're right, I was probably mislead this whole time. I went through my old analysis class book [1] and there doesn't seem to be an explicit definition of elementary functions. The best I can find is this paragraph (I translate from italian):
The elementary functions of analysis, that is powers, roots, exponentials, logarithms and their inverses, functions obtained from the former by arithmetic operations or composition, admit the limit f(p) for x → p, for any p in their set of definition. The study of such functions, which is not limited to the sole real functions of real variable, is carried out naturally in the setting of metric spaces.
That said, I'm relatively sure that a definition was given in class and it didn't include arbitrary roots: despite being notoriously difficult, the exam didn't require students to draw the graph of any elementary function including implicitly-defined algebraic roots.
I picked up another one of the old recommended books [2] and it seems to be similarly vague; while the book currently taught in my university [3], gives this definition:
The following functions (from ℂ to ℂ) are called the elementary functions of the Analysis:
1) Rational functions (integral or fractional)
2) Algebraic functions (explicit or implicit)
3) The exponential function
4) The logarithm function
5) All those functions that can be obtained by combining a finite number of times the functions of kind 1)...4).
So, roots of arbitrary polynomials implicitly defined are indeed considered elementary. I never knew this.
[1] https://search.worldcat.org/title/1261811544
My concern is that the word “elementary” in the title carries a much broader meaning in standard mathematical usage, and in this meaning, the paper’s title does not hold.
Elementary functions typically include arbitrary polynomial roots, and EML terms cannot express them.
If you take a real analysis class, the elementary functions will be defined exactly as the author of the EML paper does.
I've actually just learnt that some consider roots of arbitrary polynomials being part of the elementary functions before, but I'm a physicist and only ever took some undergraduate mathematics classes. Nonetheless, calling these elementary feels a bit of stretch considering that the word literally means basic stuff, something that a beginner will learn first.
aren't exp and ln really primitives? Aren't they implemented in terms of +,-,/,* etc?
They're primitive in the sense that you can't compute exp(x) or log(x) using a finite combination of other elementary functions for any x. If you allow infinite many operations, then you can easily find infinite sums or products of powers, or more complicated expressions to represent exp and log and other elementary functions.
Or do we assume that we have an infinite lookup table for all possible inputs?
Essentially yes, you don't necessarily need an "implementation" to talk about a function, or more generally you don't need to explicitly construct an object from simpler pieces: you can just prove it satisfies some properties and that it is has to exist.
For exp(x), you could define the function as the solution to the diffedential equal df/dx = f(x) with initial condition f(0) = 1. Then you would enstablish that the solution exists and it's unique (it follows from the properties of the differential equation), call exp=f and there you have it. You don't necessarily know how to compute for any x, but you can assume exp(x) exists and it's a real number.
I'm not sure what happens to the socket, maybe it's closed and reopened, but with this patch I have SSH sessions lasting for days with no issues. Without it, even roaming between two access points can break the session.
I think it does, but that's not the issue: if the interface goes down all the temporary address are gone for good, not just "expired".
Well, yss, but SSH is hardly ever anonymous and this could simply be a cli option.
See this, for example: https://groups.google.com/g/opensshunixdev/c/FVv_bK16ADM/m/R...
It boilds down to using a Linux-specific API, though it's really BSD that is lacking support for a standard (RFC 5014).
Well, for different reasons, but you have similar issues with IPv6 as well. If your client uses temporary addresses (most likely since they're enabled by default on most OS), OpenSSH will pick one of them over the stable address and when they're rotated the connection breaks.
For some reason, OpenSSH devs refuse to fix this issue, so I have to patch it myself:
--- a/sshconnect.c
+++ b/sshconnect.c
@@ -26,6 +26,7 @@
#include <net/if.h>
#include <netinet/in.h>
#include <arpa/inet.h>
+#include <linux/ipv6.h>
#include <ctype.h>
#include <errno.h>
@@ -370,6 +371,11 @@ ssh_create_socket(struct addrinfo *ai)
if (options.ip_qos_interactive != INT_MAX)
set_sock_tos(sock, options.ip_qos_interactive);
+ if (ai->ai_family == AF_INET6 && options.bind_address == NULL) {
+ int val = IPV6_PREFER_SRC_PUBLIC;
+ setsockopt(sock, IPPROTO_IPV6, IPV6_ADDR_PREFERENCES, &val, sizeof(val));
+ }
+
/* Bind the socket to an alternative local IP address */
if (options.bind_address == NULL && options.bind_interface == NULL)
return sock;The magnetron itself has about about 65% efficiency, but the paper conjectures that the longer duration of the pulses is due to defects in the cavity that result in some emission at a lower frequency (1.4 rather than the normal 2.4 GHz), so the energy radiated must be a tiny fraction of the nominal power.
What is the point of restricting a certificate to "server" or "client" use, anyway?
I have been using GitHub since 2011 and it's undeniable that the performance of the website have been getting worse. The new features that are constantly being added are certainly a factor, but I think the switch to client-side rendering that obviously shifted the load from their server to our browsers and also tend to produce ridiculously large and inefficient DOMs[1] is the main cause.
If you want a practical example, here you go. I'm a Nixpkgs commiter and every time I make a pull request that backports some change to the stable branch, GitHub unprompted starts comparing my PR against master. If I'm not fast enough to switch the target branch within a couple of seconds it literally freezes the browser tab and I may have to force quit it. Yes, the diff is large, but this is not acceptable, and more importantly, it didn't happen a few years ago.
MSS clamping is non-negotiable with tunnels. Every layer of encapsulation eats into the MTU.
Can this tunnel be avoided somehow? If I have to choose between owning my prefix and having 1500 MTU, I'd probably take the latter: MTU issues are so annoying to deal with, and MSS-clamping doesn't solve all of them.
Traceroutes are already notoriously hard to interpret correctly[1] and yes, they can be trivially spoofed. Remember the stunt[2] pulled by tpb to move to North Korea? If you are an AS you can also prepend fake AS to your BGP announcements and make the spoofed traceroute even more legitimate.
I wonder if this thing will start a cat and mouse game with VPNs.
[1] https://old.reddit.com/r/networking/comments/1hkm4g/lets_tal...
Barely? It's more than twice the mediage wage in Poland.
I had a lot of fun playing around with antimony (also from Keeter) a few years ago, but unfortunately it has been mostly abandoned. I heard libfive is supposed to be the next generation, but I haven't experimented with it yet.
Do you know how it compares?
this could invalidate the information contained in that in the man file.
No, it doesn't. The point of modetc is precisely keep both myself and the programs happy: the files are actually stored where I like to keep them, but they can be accessed as if they were stored where the developer intended.
Why would I hide them? They're not really special and since I'm organising them with modetc they're not cluttered. For reference, my home looks something like this
~
├── bin binaries and scripts
├── etc configuration files
├── var
│ ├── lib program data
│ └── cache program caches
├── src git repositories
├── img pictures
├── mail email in maildir format
├── note text notes, todo
├── doc documents
└── down downloadsWell, it's just the natural extension of the FHS convention to the home directory.
I didn't come up with this idea, though, I think I saw this in a reddit thread and started doing it myself: I like that the directories are visible and follow the usual structure.
Hi, author here: whether it's a valid use case depends on your level of OCD, but the difference compared to symlinks or bind mounts is that you will have a clean home: e.g. `ls -la` won't show any "hidden" files.
Also, completely unrelated to my motivation, someone pointed out that modetc could be used to quickly hotfix packages built with Nix. Say that you need to fix a CVE in openssl, normally that would require to rebuild all dependent packages, which takes a long time. Instead with something like modetc you could build just openssl and rewrite /nix/store/<hash>-openssl-3.6.0/ -> /nix/store/<hash>-openssl-3.6.0-hotfix/.
Another application might be replacing some configuration file with placeholders for secrets, with one file with the secrets substituted in, without having to modify it in place, possibly only for a specific UID. This is something you might find useful on NixOS.