Re: [gentoo-user] Shell echo missing after ctrl+c

[Alan Mackenzie]

Hello, Kai.

On Sun, Mar 19, 2017 at 09:49:50 +0100, Kai Krakow wrote:
> Hello!

> More and more of my Gentoo systems are exhibiting the following
> strange and unexpected behavior:

> After ctrl+c'ing out of programs like tailf, SSH password prompts, in
> the middle of a shell scripts, the shell echo is not restored - that
> is: If I type characters I no longer see the characters (but they are
> received and can be executed by "enter"). If experiencing this, I have
> to ctrl+c again to discard what I was typing, the blindly type "reset"
> to reset the terminal, then echo is enabled again.

> I'm not sure which update or configuration is causing this. It started
> out on our Gentoo servers some years ago (which I'm only SSH'ed into,
> no physical access), now since a few weeks, also my desktop machines are
> affected. I have no explanation for this.

> But maybe anyone?

> BTW: I know from the old times (some 15-20 years ago) that ctrl+c out
> of a program (i.e. rsync) that starts a subshell (i.e. ssh) that in
> turn shows a password prompt, will leave you with an echoless shell.
> But it shows up on almost any occasion now.

It's been happening to me increasingly often in the last few
months/years.  I don't like it.

Here is a recipe for reproducing the phenomenon.  A typical way of
invoking patch is by supplying the patch file to standard input:

    $ patch --dry-run < some-patch-file.diff

.  However if you accidentally omit the "<", like this:

    $ patch --dry-run some-patch-file.diff

, the terminal will await you typing in the patch file.  Instead, do a
ctrl-c.  This leaves the terminal not echoing keystrokes.

By the way, thanks for educating me about the existence of the command
`reset'.  :-)

> --
> Regards,
> Kai

> Replies to list-only preferred.

-- 
Alan Mackenzie (Nuremberg, Germany).