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

[Kai Krakow]

Am Sun, 19 Mar 2017 11:37:56 +0000
schrieb Alan Mackenzie <acm@×××.de>:

> 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.

Me neither, getting on my nerves.

> 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.

The "funny" nature of this bug is its "reproducibility": On my system,
your test doesn't work for me: I currently always get echo back. Tho,
next reboot that may have changed.
 
> By the way, thanks for educating me about the existence of the command
> `reset'.  :-)

Enjoy. :-)

There's a maybe related problem: On some system I see that tailf
doesn't detect new file data - sometimes never, sometimes it stop after
a while, and I checked: The file wasn't rotated or truncated. That also
affects apachetop which reliably never works on this system. Fun fact:
Only one user was affected by this, now also my own user is affected.

-- 
Regards,
Kai

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