Letterbox mode

letterbox-mode is a simple minor mode to add letterboxing to sensitive text.

Select a region of text you want to censor and call M-x letterbox-add, the selected region will be letterboxed/censored.

Call M-x letterbox-remove to remove all letterboxes, or M-x to toggle the letterboxes (without removing them).

Use cases

This is a buffer with some sensitive information. 123456 is the password for my bank account, and qwerty is my account name. please don't read it.

Select "123456" and call letterbox-add, you will see that part letterboxed:

This is a buffer with some sensitive information. ██████ is the password for my bank account, and qwerty is my account name. please don't read it.

Select "qwerty" and call letterbox-add again, you will see that part letterboxed as well:

This is a buffer with some sensitive information. ██████ is the password for my bank account, and ██████ is my account name. please don't read it.

Call letterbox-toggle to hide/show the sensitive text, or letterbox-remove to remove them.

Default keybindings

C-c a -> letterbox-add
C-c r -> letterbox-remove
C-c t -> letterbox-toggle