4 ms·

When you think about how a typewriter works it's actually correct. The "newline" handle does both a carriage return and a line feed. But you could conceivably d

When you think about how a typewriter works it's actually correct. The "newline" handle does both a carriage return and a line feed. But you could conceivably do a carriage return without a line feed (and type over what you already have), or a line feed without a carriage return (which might have some actual use).

Turing_Machine 10y ago
One use for CR without LF was to overstrike passwords on printing terminals. You'd enter your password (which would appear on the paper) then the system would go through several rounds of issuing a CR followed by overstriking the password with random characters.
- radarsat1 10y ago
  I still use CR without LF all the time. If I'm writing something that features a long loop, I might want status updates, so printf("%d \r", percentage); helps tremendously. You'll need to fflush(stdout) too, since usually flush is triggered by "\n". On the other hand, there are far fewer use cases for LF without CR, certainly nothing that isn't better done using ANSI codes.
  - torrent-of-ions 10y ago
    This the use of CR without LF on a virtual TTY. On a real TTY or typewriter there is less use, but as one user pointed out one could remove information like a password which was printed. LF without CR is something that one would do on a typewriter for typing tabulated data or mathematical formulae. It's just a way to go "down" but stay at the horizontal position you were previously at.
JdeBP 10y ago
It's not just conceivable. It's how the output of grotty in TTY-37 mode works to this day. When you are reading a manual with underlining and boldface, and you haven't brought your manual system into the bold new GNU world of the 1990s where it actually uses ECMA-48 instead of TTY-37, the tty output driver is using carriage returns and backspaces to enact overstrikes. * http://jdebp.eu./Softwares/nosh/italics-in-manuals.html http://jdebp.eu./Softwares/nosh/italics-in-manuals.html I wrote a better manual page for ul(1) that explains some of this. ul is basically a TTY-37 to your-terminal-type converter, and it implements a lot of the effects that one would see on a real teletype. Unfortunately, the old manual hasn't progressed much beyond the original 1970s one and doesn't explain a lot of the functionality that the program actually has. * http://jdebp.eu./Proposals/ul.1 http://jdebp.eu./Proposals/ul.1

Turing_Machine 10y ago

One use for CR without LF was to overstrike passwords on printing terminals. You'd enter your password (which would appear on the paper) then the system would go through several rounds of issuing a CR followed by overstriking the password with random characters.

radarsat1 10y ago
I still use CR without LF all the time. If I'm writing something that features a long loop, I might want status updates, so printf("%d \r", percentage); helps tremendously. You'll need to fflush(stdout) too, since usually flush is triggered by "\n". On the other hand, there are far fewer use cases for LF without CR, certainly nothing that isn't better done using ANSI codes.
- torrent-of-ions 10y ago
  This the use of CR without LF on a virtual TTY. On a real TTY or typewriter there is less use, but as one user pointed out one could remove information like a password which was printed. LF without CR is something that one would do on a typewriter for typing tabulated data or mathematical formulae. It's just a way to go "down" but stay at the horizontal position you were previously at.

JdeBP 10y ago

It's not just conceivable. It's how the output of grotty in TTY-37 mode works to this day. When you are reading a manual with underlining and boldface, and you haven't brought your manual system into the bold new GNU world of the 1990s where it actually uses ECMA-48 instead of TTY-37, the tty output driver is using carriage returns and backspaces to enact overstrikes. * http://jdebp.eu./Softwares/nosh/italics-in-manuals.html http://jdebp.eu./Softwares/nosh/italics-in-manuals.html I wrote a better manual page for ul(1) that explains some of this. ul is basically a TTY-37 to your-terminal-type converter, and it implements a lot of the effects that one would see on a real teletype. Unfortunately, the old manual hasn't progressed much beyond the original 1970s one and doesn't explain a lot of the functionality that the program actually has. * http://jdebp.eu./Proposals/ul.1 http://jdebp.eu./Proposals/ul.1