C-q not working in bash. How to debug?

Hello, everyone!

My problem is a bit strange.

I (as, I guess, many people) have a stock slackware64's default bash shell and stock /etc/inputrc.

I am trying to use the default keybinding for "quoted-insert", which is:

"\C-q": quoted-insert

However, literally typing C-q does nothing. C-q C-l refreshed the screen instead of displaying ^L.

This behaviour is reproducible in xfce4-terminal, xterm, uxterm, and C-M-F* consoles, but is NOT reproducible in any of those is using ksh. (Which doesn't use GNU Readline, as far as I know.)

C-v and the \e-sequence are working just fine. Is it that C-q is not going through Readline for some reason?

Originally Posted by Lockywolf However, literally typing C-q does nothing. C-q C-l refreshed the screen instead of displaying ^L.

C-q (and the companion C-s) may be used for tty flow control. C-s stops the flow and C-q restarts it.

To disable flow control, do

stty -ixon

and C-q should be available to readline. C-q C-l should then display ^L

Originally Posted by philanc C-q (and the companion C-s) may be used for tty flow control. C-s stops the flow and C-q restarts it.

Correct, see in output of stty -a:

start = ^Q

Originally Posted by philanc C-q (and the companion C-s) may be used for tty flow control. C-s stops the flow and C-q restarts it.

This reminds me the old days. Nearly 40 years ago I managed a project at a car plant that used dedicated phone lines to communicate between the main frame and terminals (real terminals, not virtual ones) asynchronously, using Xon (aka DC1) and Xoff (aka DC3). 1200 bauds was a good enough speed then...

Originally Posted by Didier Spaier This reminds me the old days. Nearly 40 years ago I managed a project at a car plant that used dedicated phone lines to communicate between the main frame an terminals (real terminals, not virtual one) asynchronously, using Xon (aka DC1) and Xoff (aka DC3). 1200 bauds was a good enough speed then...

I still remember today my first ^S/^Q lesson: I was typing at a terminal, and it suddenly looked dead. Could type anything and nothing changed on the screen. I called a sysadmin (no help desk these days), asking if the computer was down. The guy sighed. "Control-Q" he said dryly, and he hanged up.

Got it, thanks!

I knew that C-q resumes the flow after C-s has been pressed.

But I didn't know that C-q is also intercepted if C-s has NOT been pressed.