Epstein's?

Yep, takes a moment to wrap your head around but the longer you read linux/unix documentation, the more it makes sense why it is the case.

Yeah, but in the BSD land as their licensing is more Libertarian esqu.

Want take it to 11 plan 9 did it.

Stages of POSIX enlightenment:

1. It couldn't possibly all be files
2. It's all files
3. What is a file, anyway?
4. There's no such thing as a file
5. It couldn't possibly all be files
6. Everything is a file

Most people stop at stage 2, stage 3 hits when you decide to write a filesystem, stage 4 when you've finished your first filesystem. Stage 5 is when you start working on kernel internals. No one can tell you how to reach stage 6, you must discover it for yourself.

/dev/null sez nothing is also a file

Unfortunately, no one can be told what a file is. You have to see it for yourself.

This is your last chance. After this, there is no turning back. You take the blue pill - the story ends, you wake up in your bed and believe whatever you want to believe. You take the red pill - you stay in Wonderland and I show you how deep the file system goes.

Okay, but what are blocks then? A file is really just a bunch of blocked stacked together with the inode metadata also sitting on another block, so is everything just blocks or because you can emulate a block device on a filesystem, are blocks themselves files? If that last part is true then files are infinitely recursive and my head is starting to spin.

You'll know you've reached stage 6 when you seriously start considering running Plan 9 as a daily driver

https://xkcd.com/566/

But some things are directories (like cgroups). And Networknamespaces were also controled in a weird way.
And then there are kernel features which are not exposed through a file or syscall but through a special type of socket.

You are almost ready to take the next step. But to do so, you must unlearn what you think you know. Write a filesystem that does not have blocks for a media without pages, and you will find the footprints of your next teacher.

"How can files be real if the filesystem isn't real?" - Jaden Smith (probably)

It makes more sense when you realize that it's not that everything is files it's that everything can be treated as a file. There are other APIs to interact with things, but everything can be interacted with as if it was a file. It doesn't seem as bonkers like this.

Well, if you go back far enough you might encounter punch cards or even switches, but then again you're not taking about modern computers anymore.

Am I a file?

Aren't directories just files that say "hey i am directory ABCD and file X, Y and Z are my childs"?

Can you read me?

Files? In my Linux?

It's more likely than you think.

Directories are just files if you squint at then right, and sockets are basically files too. As another commenter said, it's not that everything is literally a file, but that it presents as a file, and can be interacted with as one.

And the hidden 0th level that you only get after being nearly killed by a falling server rack:

"Files Aren't Things"

Which looks great on a tshirt, btw :p

What's this "back far enough" shit, I've used punch cards and punch tape.

Fuck me I'm old.

Asking for a friend.

If you can recognize "nothing" then "nothing" must be something right? So if nothing is a file, because /dev/null says so, then nothing MUST be something to be a file. And therefore /dev/null can't be nothing.

Or do I just need more tea? Or maybe whisk(e)y?

That way lies madness!

To feel really old: http://themindsetlist.com/lists/

Missing stage 7: Not everything is a file.

Linux is closer than other *nixes (sysctl equivalents in some platforms are not files, but they are files in Linux).

However get very far into network and the file-like behaviors become more limited. From an application, at least you have a decent chance of having unseekable, but otherwise 'file-like' interaction with stream protocols. Then you need recvmsg/sendmsg. Then you want to deal with low level interaction with the network stack and dealing with NETLINK and such..

The devnode that is used to reference the block is a file, so you come back to blocks just 'being offsets into some file'.

Though system calls, ioctls and networking credibly get away from file semantics

The word "nothing" isn't itself nothing. It is something used to describe nothing.

Exactly. A file is really just a way to understand a collection of bits. So saying everything is files is like saying everything in computers can be described as sets of bits, which is not a terrible heuristic.

A file would be something. No, it was nothing.

That's funny. I have a pair of Converse tennis shoes that are 27 years older than that list......

The word "nothing" is the English word describing the concept of nothing. And I have to use the word to describe the concept. So yes, you are correct the word is itself "something". So that is probably one point for "nothing" to not exist.

I have now consumed 3 cups of tea. And my head now hurts from thinking about nothing. I should never have stepped into this post.

It's like saying everything is a wave IRL.

true enlightenment: everything is a string over an IO socket

it's just a sentinel value. You ve
reached the end. gimme back the length

The length is a null value.

oh god oh no oh god oh no i am gonna crash

in fact that gets used in abstract mathematics to first introduce the natural numbers. the empty set (nothing) (which you define as 0) is not itself nothing, so you can define the set that contains just the empty set, which now is not empty itself, but contains one element, so you define that as 1 ...

tldr: it's to have nicer, less complicated I/O operations

it enables just having two API calls: read() and write() to do everything

Files don't actually exist once you dig down

Hope your name isn't Peter

Especially the particles

But what about the fotoes?

I suspect sarcasm but in case it is not, photos are just binary files, just like videos and many other file formats.

Yeah, it sort of depends on the definition of the word file. "File" in the sense that it can be interacted with like a file versus "file" in the sense that it's data on a disk. But then, if you're really thinking about it, data on a disk isn't a file, it's data, and we can just interact with it like a file.

That's where plan9 comes in!

1. Everything is a FIFO

Bro stop digging I need those files to keep existing

In Windows land, it's HANDLEs...which is typedef void* HANDLE IIRC