coreutils VS WSL

https://github.com/coreutils/coreutils/commit/fcfba90d0d27a1...

A summary of other changes just released in GNU coreutils 9.5 are:

* mv accepts --exchange to swap files

> some are simple like yes(1)

Not that simple: https://github.com/coreutils/coreutils/blob/master/src/yes.c

The -S / --split-string option[1] of /usr/bin/env is a relatively recent addition to GNU Coreutils. It's available starting from GNU Coreutils 8.30[2], released on 2018-07-01.

Beware of portability: it relies on a non-standard behavior from some operating systems. It only works for OS's that treat all the text after the first space as argument(s) to the shebanged executable; rather than just treating the whole string as an executable path (that can happen to contain spaces).

Fortunately this non-standard behavior is more the norm than the exception: it works at least on modern GNU/Linux, BSDs, and macOS.

[1] https://www.gnu.org/software/coreutils/manual/html_node/env-...

[2] https://github.com/coreutils/coreutils/blob/b09dc6306e7affaf...

> building a cat from scratch

> That would be an interesting project.

Here is the source code of the OpenBSD implementation of cat:

> https://github.com/openbsd/src/blob/master/bin/cat/cat.c

and here of the GNU coreutils implementation:

> https://github.com/coreutils/coreutils/blob/master/src/cat.c

Thus: I don't think building a cat from scratch or creating a tutorial about that topic is particularly hard (even though the HN audience would likely be interested in it). :-)

the yes command, writing to /dev/null, is making IO calls, which interfere with predictable scheduling.

If you look at the source code for yes, https://github.com/coreutils/coreutils/blob/master/src/yes.c

it builds a buffer of output and then writes that in a for loop

  while (full_write (STDOUT_FILENO, buf, bufused) == bufused)

Looking at the source of nohup, if the execvp() of the child happens then it _must_ have already done the signal (SIGHUP, SIG_IGN) so - WTF?

This got me wondering so I went and looked and it seems like lo and behold there was actually a commit to the GNU ls source just 2 weeks ago.

https://github.com/coreutils/coreutils/blob/master/src/ls.c

"maint: prefer char32_t to wchar_t"

even an empty file? Yes. so now it was a file with a copyright disclaimer and nothing else. And the koan-like question comes to mind is "Can you copyright nothing?" well AT&T sure tried.

Then somebody said our programs should be well defined and not depend on a fluke of unix, which at this point was probable a good idea. so it became "exit 0"

Then somebody said we should write our system utilities in C instead of shell so it runs faster. openbsd still has a good example of how this would look.

http://cvsweb.openbsd.org/cgi-bin/cvsweb/~checkout~/src/usr....

At some point gnu bureaucracy got involved and said all programs must support the '-h' flag. so that got added, then they said all programs must support locale so that got added. now days gnu true is an astonishing 80 lines long.

https://github.com/coreutils/coreutils/blob/master/src/true....

http://trillian.mit.edu/~jc/humor/ATT_Copyright_true.html

> Yes, ls is maintained. Although, maintained is a very strong word. It exists.

Why would it be a strong word? Here it is, in src/ls.c: https://github.com/coreutils/coreutils

It is then packaged by tens of operating system distributions, who themselves maintain extra patchsets, some of which are then upstreamed.

It is installed and used on millions (billions?) of devices, for 3 decades.

It's a very reliable and trusty "sharp stick of metal" :)

It absolutely 100% can be true.

As an example: Windows Services for Linux 2 used a special init daemon to interact with the host OS.

That meant no systemd. That meant that the `systemctl` program wasn't there.

This baffled legions, armies, of wannabe sysadmins.

https://stackoverflow.com/questions/55579342/why-systemd-is-...

https://superuser.com/questions/1785697/systemd-in-wsl-on-wi...

https://github.com/microsoft/WSL/issues/9477

https://askubuntu.com/questions/1132230/unable-to-run-any-sy...

People on the whole have no idea how this stuff works, and they just copy magic incantations from StackOverflow to get stuff to happen. If that doesn't work, then this OS is broken. The end.

For these guys, WSL was broken.

Result:

MS hired Lennart Poettering.

https://www.theregister.com/2022/07/07/lennart_poettering_re...

He "fixed" it. Systemd now works in WSL2. All those guides for noobs now work. Everyone is happy.

In a world where tools like Flatpak and Snap are proliferating and it's driving deep divisions between Linux distros, if you think the average person struggling with Linux is going to use `ldd` to work out where the dependencies for something live, I'm afraid you are a deep guru who lives on a different plane of existence.

We now have widely-used packaging systems which simply embed an apps entire dependency tree into a package to avoid people having to work out the difference between `apt` and `rpm`. Thousands of terabytes of disk are being burned to make this stuff go away.

Yes, this is too hard. Way too hard.

Better source: https://github.com/Microsoft/WSL/issues/873#issuecomment-425...

One of the bugs where on the Docker side. As I have said, there have been several since release with a lot of impact period overlap. The latest and greatest is not resolved.

It's the issue of abysmal I/O performance in communication between the mounted WSL2 virtual hard disk and Windows mounts inside the WSL2 distro.

I found this github page and I was able to reproduce this from the answer

* Docker engine and not Docker Desktop in a VM. WSL2 works well after some configuration: https://github.com/microsoft/WSL/issues/6655#issuecomment-11...

Seems to more of a Defender issue than a WSL one, see https://github.com/microsoft/WSL/issues/8995

After adding exclusions for the fsnotifier-wsl process and and both variants of the WSL distro path my disk performance was improved.

Adding the idea64.exe process also helped since I was trying to run IntelliJ against projects inside WSL.