I'm currently running a Xubuntu image using VirtualBox and a strange issue just started occurring: I cannot enter a or c in a terminal or terminal emulator. A and C (that is, a/c + left/right Shift or with Caps Lock active) work just fine, and a/c work fine in graphical applications; it's only when using the full terminal or xfce4-terminal/xterm that the keys don't work. This seems to be a user-specific thing, as I can use a and c just fine when entering the user name for login at a terminal but once logged in the keys no longer work; however, I cannot figure out what settings I changed to somehow cause it.

Additional info: the characters are also filtered when pasting text into a terminal emulator; for a moment, I was able to get a to paste as part of a string when it was at the front, but I'm no longer able to.

  • What shell are you using?
    – jimmij
    Sep 13, 2015 at 22:31
  • @jimmij GNU bash, version 4.3.30(1)-release (x86_64-pc-linux-gnu)
    – JAB
    Sep 13, 2015 at 22:33
  • If you run tee in that terminal, can you type a and c? Sep 13, 2015 at 22:40
  • @Gilles Yes, and I can also paste them in. This also works if I run a terminal program such as vim, etc.; it seems to be limited to the command line/shell itself.
    – JAB
    Sep 13, 2015 at 22:41
  • Start bash with options --noprofile --norc, same result?
    – jimmij
    Sep 13, 2015 at 22:48

1 Answer 1


Since this problem occurs on different terminal types, and occurs at a command prompt but not when some other program is reading from the terminal, this is a configuration problem in your shell. You've accidentally defined bindings for a and c.

Assuming that your shell is bash (the default interactive shell on Ubuntu), check the two relevant configuration files in your home directory:

  • .inputrc, the configuration file for the readline library, which bash uses. Look for a line starting with a and a line starting with c.
  • .bashrc, the configuration file for bash when it runs interactively. Look for a line containing bind a… and a line containing bind c….
  • There aren't any lines like that in either .bashrc or .inputrc.
    – JAB
    Sep 13, 2015 at 22:58
  • Ah, but it was an .inputrc issue after all. I forgot to put set before some variable assignments. Silly me.
    – JAB
    Sep 13, 2015 at 23:04

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