unix-history-repo VS coreutils

There is also https://github.com/dspinellis/unix-history-repo (Continuous Unix commit history from 1970 until today)

FWIW, ls in Research-V6 back in 1975 had 10 options. https://github.com/dspinellis/unix-history-repo/blob/Researc...

By BSD 3 in 1980 it had 11 options. https://github.com/dspinellis/unix-history-repo/blob/BSD-3-S...

The thing is, we can see even from the 1970s 'ls' how the Unix model doesn't meet the goal "to chain these simple programs together to create complex behaviors".

There is no option to escape or NUL terminate a filename, making it possible to construct a filename containing a newline which makes the output look like two file entries.

The option for that was added later.

There's also the issue that embedded terminal codes will be interpreted by the terminal.

This is what it looked like about 7-8 years earlier: https://github.com/dspinellis/unix-history-repo/blob/BSD-1/e...

RA92 (1989): 16 ms / 8.3 ms.

Note that the RL02 (and V7) and RA92 mentioned in the article are separated by about a decade.

[1] https://github.com/dspinellis/unix-history-repo/blob/Researc...

The earliest version I could find [1] is already written in C.

[1] https://github.com/dspinellis/unix-history-repo/blob/Researc...

Here's a 1997 citation for "top cpu processes." It's not as close to the original 1984 release as I would like, but it's better than Wikipedia. https://github.com/dspinellis/unix-history-repo/commit/aee34003d7964653c44c31f5bf6bcf136b32c4f3

> The “why” goes into the PR and more importantly, engineering documentation and inline comments

This just ensures that the “why” is lost when someone comes looking years later.

From experience, SCM metadata is far more durable than just about any other work product we produce. Five decades later and RCS commit info was still available for the Unix sources, and history could be reconstructed: https://github.com/dspinellis/unix-history-repo

I’ve used 35-year-old commit messages to help understand a long-standing issue, decades after all other related organization tooling and data had disappeared.

P.S. I remember I looked into early versions of C (they survived in Unix historic releases) and that, finally, revealed to me why C does something really stupid and conflates arrays and slices (pointers). Initially C had no arrays! Or, rather, what it called arrays were, actually, pointers. “Normal” arrays were added at some point, but because these weird slices/pointers were already there that caused endless confusion. It wasn't resolved before C became popular and after that it was too late. Go repeated that mistake with slices, of course.

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" :)