[thatcks]

Raw mode by itself is essentially useless for almost all programs; in order to do anything with it, you already need an entire surrounding collection of code to handle editing (even basic things like backspacing) and so on. But line-oriented input remains useful on its own without additional user-level code, again precisely because of the editing support the kernel already provides for you. Since you already need user level code to make any real use of raw mode, the user level code can also set things into (and out of) raw mode as you need it, so line mode remains a sensible default.

If anything things should move the other way, with the kernel providing more readline-style line editing in 'line mode' so that programs need to implement less of it themselves. But this would provoke all sorts of arguments over what line editing the kernel should support and so on, and then someday someone will suggest that the kernel should let you implement your own in-kernel line editing using eBPF (or WASM, if one leans that way), so people could push their preferred choice into the kernel when they log in or start up a shell on a new pty.

(I'm the author of the linked-to entry.)

[JdeBP]

You are Kenneth Almquist, and I claim my five pounds.

* https://groups.google.com/forum/#!msg/comp.sources.unix/Vejy...

[thatcks]

Funny you should mention that:

  ; ls -l <archives path elided>
  -rwxr-xr-x. 1 cks man 65536 Dec  4  1991 ./bin/bin.ultrix-mips/atty

I see that GIDs around here have drifted a bit over the years.