Retire SRM (send/receive mode = monitor)?
ECMA-48 § 7.2.15:
SRM - SEND/RECEIVE MODE MONITOR [low]: Data which are locally entered are immediately imaged. SIMULTANEOUS [high]: Local input facilities are logically disconnected from the output mechanism; only data which are sent to the device are imaged.
Enter this mode using
echo -ne '\e[12l', start
cat (which appears as
ccaatt) and type some text.
Backspace (^?) and ^H are handled differently than in xterm, we echo back stuff that xterm doesn't.
xterm doesn't properly echo back UTF-8 locally, produces "double UTF-8" or so.
The Linux console, Konsole, Urxvt, Kitty, Terminology, Screen, Tmux don't support this mode. (Xterm, Putty, Mlterm, St do.)
I assume this is a legacy thing not in use anymore. Can we get rid of it? :)