Hi,

I'm experiencing an annoying issue with keyboard lag when I'm typing in a terminal. If I type an 's' character after any other character, it takes about half a second to show up. If I type another character immediately after the 's' character, they both show immediately.

I'm running ubuntu-gnome 16, and I'm experiencing this in xterm, gnome-terminal and terminator. When I switched to tty1, I had the same behaviour only after I logged in.

This behaviour does not show when I switch to dash or zsh. However, if I start a python shell, the 's' character doesn't show up at all until I type a next character, in an ipython shell this phenomenom does not occur.

When I switch to the root user none of the above problems occur.

Maybe some setting in the specific user's .bashrc or .bash_profile that is different from root user's? Some sort of key definition in one of those making it determine if you're going to do something else (e.g. sticky key, alias that starts with s, etc...)?

I use bash all day, every day, and haven't seen the behavior you describe.

Years ago, I did see that kind of behavior on all characters in sh/ksh on UNIX when we were doing token ring via satellite to remote sites. 1/4 second doesn't sound long until you have to wait for every character to echo back in full duplex mode. Switching to half-duplex helped but then you'd have to make sure you had no typos before hitting enter.

Sounds a bit like your locale (language/keyboard setting) supports a multi-key sequence that starts with the "s" key, so the input handler is waiting to see IF you complete the sequence (and then echoes the composed char) or this was just a bare "s".

It's wise to rule out hardware in cases like this. If you have another keyboard that you know works, swap it and see if the problem persists

Also, pop the cover off the key to make sure that some bit of debris has not worked its way under the key.

I've attached some different usb keyboards and ssh'ed into my laptop from a different machine, the issue still persists, so a hardware problem can be ruled out. I've also tried sourcing my .bashrc from the root user account, which didn't trigger the weird behaviour I see on my own user account so it's probably not something in there.