If I run
read -r -s INPUT
And then interrupt it with Ctrl-C, then the terminal stays in a state where all the input characters are not shown.
How can I restore the terminal after such an incident?
The command used to reset the terminal is aptly named:
However, this would likely clear the terminal as well.
You may also try
which would turn on echoing of what you type, or
which should get your terminal back into a sane state.
If the Enter key does not seem to work, you may use Ctrl+J instead.