[anitil]

Annoyingly I actually think '\r\n' is the correct line ending here - advance the paper and return the carriage, but I suppose unix took the simpler implementation which makes looping over characters, words (split by ' ') and lines (split by '\n') simpler as each loop only has a single comparison

[spauldo]

The carriage return and linefeed combo are the commands to move to the next line of a teletype. Other commands might (in theory) be used for this purpose on other devices. These are implementation details.

Text inside a computer doesn't need any of that just to signal a newline. UNIX chose to use a single line feed character as a line separator because there was no good reason to use two. MacOS chose a single carriage return for similar reasons. Anything going out to a printer or teletype would run through a device driver that would turn the newline character into whatever the device expects.

Windows copied DOS which copied CP/M which was a very basic program loader for 8-bit machines and didn't really have "drivers" like we think of them today. I'm guessing here, but I imagine they chose the teletype combo because that's what most serial printers understood and printing was a major use case for those machines. That was probably the right choice for CP/M, but I can't imagine Microsoft would choose it if they were developing Windows from scratch today.

[Joker_vD]

Yep, on Unixen the translation of CRLF to LF when printing to the terminal (and from CR to CRLF when reading input from the terminal) is done in the kernel, it's called "line discipline".

[poizan42]

And if you switch the tty from "cooked" to "raw" mode then it doesn't do the conversion, and a CR just moves the cursor back to the start of the line and a LF just moves the cursor one line down.

[fragmede]

Which is how you do the fun spinny icons on the command line without having to invoke ncurses!

[freedomben]

You can also just use a \r directly without a \n. For example:

    spin='/-\|'
    while true; do 
      i=$(( (i+1) % 4 ))
      printf "\r${spin:$i:1} Working..."
      sleep 0.1
    done

[freedomben]

By the way yes, that is a subtle reference to the TOS computer, so it's best read in that voice :-)