Readline bindings not working with Control and Shift modifiers

Question

I'm tweaking with GNU Readline's key bindings in Bash. Specifically, I wish to achieve the following mapping effect:

Control' ==> 'I'

ControlShift' ==> "I"

Control` ==> `I`

Control[ ==> [I]

ControlShift[ ==> {I}

where I indicates the cursor position after expansion.

I have tried the following configuration in my ~/.inputrc. However, only the <C-`> mapping works as expected:

$include /etc/inputrc
$if mode=emacs
"\C-\'": "\'\'\C-b"
"\C-`": "``\C-b"
"\C-\"": "\"\"\C-b"
"\C-{": "{}\C-b"
"\C-[": "[]\C-b"
$endif

I'm wondering what is wrong with my configuration and how to make these mappings correctly (if possible)?

Answer 1

In a terminal, you generally cannot get all combinations of control- and shift-modifiers to be different values:

• the basis for control and shift is from US-ASCII (and similar) schemes which defines control and shift for the alphabetic characters plus a few punctuation characters.
• the combination control+shift usually has no effect, except for special keys.
• some terminals define escape sequences for control/shift with special keys (such as cursor- and function-keys). The tab key is not one of those keys.

Here is a screenshot to illustrate the control characters using ASCII: