Because that would not reduce code duplication. I don't know if you have ever worked on any of the low-level Linux libraries written in C, but the amount of unnecessary code duplication across them is awful. The standard library features provided by glibc are extremely inadequate for modern applications, every non-trivial C project I've seen starts to include their own private implementations of various C++ things like hashmaps, binary trees, dynamically sized strings, unicode support, async event loops, etc.
For utilities that have to interact with low level kernel APIs it's even worse, every library seems to have to reimplement their own parsing of various other random things like netlink, or in the various pseudo filesystems like sysfs, procfs, cgroupfs, etc etc, the situation is really way out of hand. I don't know how to solve this in a reasonable manner beyond what systemd is already doing. Yes people will complain that they have a systemd dependency now but what else can you do? This is the exact reason the BSDs update the kernel, libc, init and core utils in tandem and consider a lot of the kernel API to be private, Linux was just slow to catch on in that regard.
I don't want to call you out for making a disingenuous argument, but it was either subsumed by systemd for code duplication reasons, or it wasn't?!
Duplicate code, could be refactored out to a shared library, that could then be incorporated in both udev, and systemd. That would mean, anyone looking to incorporate udev into a system, could do so without depending on libsystemd.
Instead, it would seem udev code, has been subsumed by libsystemd (in your own words) - which would appear to the sceptical eye, as a power play on the part of red hat - to force other distributions into using libsystemd, which would logically end with them also using systemd itself.
> I don't know if you have ever worked on any of the low-level Linux libraries written in C [...]
The issue is not with the actual udev device event logic itself, but with all the other bits I talked about. Those are the things that would need to be duplicated.
>to force other distributions into using libsystemd, which would logically end with them also using systemd itself.
As I said elsewhere, libsystemd is just a library with some generic functions provided for convenience. This is like saying that installing python libraries on your system logically means that the PSF is trying to take over your system and forcibly rewrite everything in python, it doesn't make any sense.
Why can't there be a libredhat that provide these things to the community with a stable interface?
Lots of communities manage to have widely used data-structure and algorithm libraries that aren't closely in the same repo as other unrelated projects, is there some special problem with this kind of systems programming that prevents that?
Does it really make a difference whether it's called libsystemd or something else? If you're talking about the other functionality that's private and unstable, it's not included in a separate library for exactly that reason: it's considered private and unstable (Also I'm not sure if you're joking with that name but I really doubt there would ever be something like this literally called "libredhat," that makes about as much sense as putting a random b-tree implementation in a library called libubuntu or a libgentoo).
>Does it really make a difference whether it's called libsystemd or something else?
Probably not. But when I think of something named "libsystemd" I think of a library to interact with systemd, not a collection of random hashmap and B-tree implementations.
> If you're talking about the other functionality that's private and unstable
Why would I talk about factoring out private and unstable code into a shared library.
But if udev is depending on that private and unstable code I do have a lot more sympathy for the packagers who are wary of the merger. It's kind of disengenuois to claim that they're totally separate projects, and can reliably be deployed separately when they both depend on some private special sauce. Even if the sauce is open sourced.
> Also I'm not sure if you're joking with that name
Half a joke and half trying to avoid the "I hate the name" problem.
You have clarified a little bit of what that library is actually doing. And why it seems to make sense to have udev pick up the dependency. Thank you.
Sorry I wasn't clear -- most of the stuff I was talking about (hashmaps, b-trees, parsers, low-level utility functions, etc) is the private and unstable stuff, in the sense that it's a little too specialized towards systemd's style of C coding to warrant making it a public API, but it's useful enough to be shared between all the systemd components including udev. That's all the "private special sauce" is, it really doesn't make it any harder to deploy separately. They're not totally separate projects but there also is nothing really in common between them besides the build time dependency. Does that make sense?
You're assuming libsystemd does things which it doesn't. Saying there should've been a libudev says enough. Too much assumption the lib does loads of things around the init system part of systemd. The unneeded dislike of the library is exactly why I used to make fun of the Devuan project. Loads of decisions that pretend to be made on a technical basis, but are actually mostly emotional and "gut"-feeling.
I think you're confusing me with another poster in this thread.
I'm mildy "not a fan of systemd" in that my minimalist sense of what a "good" system is is bothered by it and it doesn't pass my "gut-feeling" but I run way more systems with systemd than without so...
The way this whole thing is divisive fascinates me though. Systemd seems to work, and work fairly well, but also attract phenomenally loud detractors. I can't think of any other piece of software that does that. Not even PHP triggers as much back and forth. This whole udev and libsystemd thing is one of the only arguments that seems technical to me.
No, you just categorically don't understand. libsystemd is not systemd the init system, it doesn't require systemd to be running, it is simply the name of "the shared library that everything developed under the systemd project uses for common code." Now, you can argue until the cows come home that you'd be happier if udev, systemd, and libredhathatesyou (or some other name for libsystemd that doesn't include systemd in it) were all in different Git repos, but since you can run udev without a dependency on systemd running on the system, that seems like a pretty low-stakes dispute.
Of course I understand, as do the rest of the people not employed by red hat upvoting me.
Time and time again, I've seen systemd advocates making slippery, disingenuous, and outright false arguments. When they're called out on it, the goalposts magically move, a rotation of usernames appear to downvote and brigade which can be ascertained through downvote timing correlation. When they can't win an argument through facts, then they make bogus arguments that one doesn't get it, or some such nonsense - or claim they're a red hat conspiracy monger.
Seeing it over and and over again is lame, and played out.
Now, why don't you answer the question - if udev was subsumed by "libsystemd" as is claimed due to "code duplication" - then why did they not just include "libudev" as a dependency for "libsystemd"?
Of course, the question will never be answered, as it'll reveal the truth.
> Of course I understand, as do the rest of the people not employed by red hat upvoting me.
That's a really poor argument you're making. You've only repeated things you've assumed earlier without actually responding or seemingly trying to understand what the other person said.
Libsystemd does not contain init system type logic. You're assuming way too much. There's too much blind hate. The suggestion that people are likely employed by Red Hat as a reason that they don't understand says enough.
Too much emotional responses to the systemd name, too often people use poor arguments and reasoning, while saying it is the other person that is lacking in their reasoning.
The code savings from including udev in systemd turned out to be greater, as there was more re-usable code already written in systemd. Please be the better person and don't revive this flamewar, it's not helpful, let's stick to the technical facts and work together to find the answers we seek -- for example you can look at the git logs to see all the shared functionality and the code that was changed around: https://github.com/systemd/systemd/tree/main/src/udev
This thread got me thinking about all the unix systems I've used, admin'd, and fought with over the years, and I suddenly remembered a system I used the early 90s when you couldn't mv a file across filesystem boundaries because what that actually was was really a copy-and-remove and not just a rename, so it was outside mv's domain.
And that's what 'the Unix Philosophy' means to me, and why I consider it not worth much.
> This thread got me thinking about all the unix systems I've used, admin'd, and fought with over the years, and I suddenly remembered a system I used the early 90s when you couldn't mv a file across filesystem boundaries because what that actually was was really a copy-and-remove and not just a rename, so it was outside mv's domain.
Many similar problems like that is exactly the reason why many systems had GNU tools installed; and "GNU's Not Unix!".
For utilities that have to interact with low level kernel APIs it's even worse, every library seems to have to reimplement their own parsing of various other random things like netlink, or in the various pseudo filesystems like sysfs, procfs, cgroupfs, etc etc, the situation is really way out of hand. I don't know how to solve this in a reasonable manner beyond what systemd is already doing. Yes people will complain that they have a systemd dependency now but what else can you do? This is the exact reason the BSDs update the kernel, libc, init and core utils in tandem and consider a lot of the kernel API to be private, Linux was just slow to catch on in that regard.