sysbox VS coreutils

Yes, I first learned this and the name "splay" from CFengine, back in the day.

I put together a small busybox-like collection of sysadmin tools, and one of the subcommands is "splay" to sleep for a random amount of time. It's one of those things that is useful surprisingly often, even outside cron.

https://github.com/skx/sysbox

I remember in 1999 there was a project to reimplement a bunch of these tools in perl:

https://perlpowertools.com/

I even contributed a little, back then. I guess writing basic versions of "ls", for example, is trivial. But there's a lot of work getting all the tools done, with all the flags implemented and behaving as expected.

I guess there are tools like busybox, toybox, and similar, which also implement a lot of "stuff" to varying degrees of completion. From my side the biggest takeaway from those projects is the sheer convenience of deploying a single binary and installing symlinks to change functionality.

I replicated something similar with my sysbox project, collecting tools together in one golang binary with various subcommands:

https://github.com/skx/sysbox

I use at least one of those tools on a daily basis, though I suspect they're not so universally useful.

If you've got perl installed you'll might have a "GET" binary present, mine is /usr/bin/GET, which comes with the WWW-module.

Although this is written in portable perl, rather than being compiled, so the static vs. dynamic choice doesn't really mean much it is a simple alternative.

Otherwise I built a simple busybox-inspired collection of tools, written in golang, which includes a simple HTTP client too:

https://github.com/skx/sysbox

Those are just a couple of examples, I'm certain there are multiple other choices out there. But I guess curl is ubiquitous enough that most people just use it directly, and add it when missing!

That's pretty cool.

I wrote something similar in my static collection of sysadmin tools - https://github.com/skx/sysbox - In my simple pre-processor I only allow two special things:

#include "file/goes/here"

I bundled together a small collection of sysadmin/scripting-tools here:

https://github.com/skx/sysbox

Those are probably amongst the things that I use most often which are non-standard.

I used to have very full ~/bin, and ~/$(hostname), directories. In the end I pared them back and started bundling things together in one binary.

The end result is very similar to this approach, I run "sysbox blah", or "sysbox help", and use integrated subcommands.

Very helpful and makes deployment easy by having only a single binary:

https://github.com/skx/sysbox

Not bash/shell, but similar and useful idea to experiment with.

I support that in my sysbox utility-box, via the subcommands processor, and it is very helpful.

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" :)