> Operating systems are currently written in C, and therefore have a C interface.

Not true. Operating systems are written in C with some assembly, and the interface to userspace is universally written in assembly. E.g., https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux...

> the interface to userspace is universally written in assembly.

Which by some eery coincidence happens to conform to the C ABI of the platform. Come on.

The point is that it has a C interface despite being written in assembly. Your original post said the only reason it had a C interface was that it was written in C.

My original sentence was "Operating systems are currently written in C, and therefore have a C interface."

I stand by that claim: the only reason operating systems have a C interface is because they are (at least originally) written in C. The fact that the kernel has some parts in assembly is immaterial, even if those parts happen to comprise the userland interface.

And it's not just the kernel: when UNIX was re-written in C, everything was written in C. The compiler, the core utilities, the editor, the shell… the whole OS, not just the kernel. Of course it was easier to interface to that in the same language everything else was written in.

Likewise, the Oberon operating system, which was written almost entirely in the Oberon language (which should have been named Pascal-3) has an… Oberon interface. Want to use C to interface with it? My, you'd have to write a whole compiler, perhaps a non-trivial runtime, debugging tools, and of course an FFI to interface to Oberon, the de-facto linga franca.

C looks much worse when it's not already the king of the hill. Its strength lies in its ubiquity more than in any quality of the language itself.

I have to say, this is one of the most patronizing comments I've come across. It's rude even by HN standards.

That certainly wasn't the intention. What part rubbed you the wrong way?

This line: "I think I do, but I'm afraid you don't. "

PS. I appreciate you reaching out and making an effort to understand why the comment seems snarky to me.

> Writing an OS (and the rest) in Pascal (I'm thinking of Oberon specifically) is no harder than to write it in C.

You can't because it is impossible to escape the type system. Without the ability to cast pointers you can't write a memory allocator. You can't write a function like dlopen()...

The "impossible" has been done: http://www.projectoberon.com/

Not sure about the memory allocator, Oberon may have avoided the problem by having a GC.

This is a nice article about the shortcomings of pascal. I don't know oberon so maybe it changed a bit.

http://www.cs.virginia.edu/~evans/cs655/readings/bwk-on-pasc...

This article talks about Wirth's Pascal as originally defined. But various language dialects evolved way beyond that, and some of them became effectively dominant.

Here's what low-level programming in Pascal looked like on DOS: http://www.retroarchive.org/swag/TSR/0022.PAS.html

Thanks for the link, I'll go take a look. I'm pretty sure Oberon addressed some of the pitfalls cited there, if only so Wirth could write an OS with it. Not every language is OS worthy, after all.