Cedilla under C (ç) in 'US international' keyboard layout in Linux

keyboard.md

Add English (US, alt. intl.)

It's because the cedilla module isn't loaded by default when the locale is set to en, so you have to change the configuration files for gtk to add them:

1. Edit configuration files:

sudo vim /usr/lib/x86_64-linux-gnu/gtk-3.0/3.0.0/immodules.cache

sudo vim /usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/immodules.cache

On both, find the lines starting with "cedilla" "Cedilla" and add :en to the line. Something like this:

"cedilla" "Cedilla" "gtk30" "/usr/share/locale" "az:ca:co:fr:gv:oc:pt:sq:tr:wa:en"

2. Change the Compose file:

sudo sed -i /usr/share/X11/locale/en_US.UTF-8/Compose -e 's/ć/ç/g' -e 's/Ć/Ç/g'

3. Instruct the system to load the cedilla module:

Add those lines to /etc/environment:

GTK_IM_MODULE=cedilla
QT_IM_MODULE=cedilla

Reboot and you are done.

source

Do you know how can I do the same for ' and ´ like you did in " and ¨ ?

Actually yes, here an example for both the "Console Key" ` and the ' apostrophe key (Credits to Levi H):

keycode 48 = dead_acute quotedbl apostrophe quotedbl apostrophe quotedbl (' á ")
keycode 49 = grave dead_tilde grave notsign brokenbar notsign brokenbar notsign (` or ~ or ã)

Just make a file in ~/.Xmodmap and add those in, if you want to test the changes beforehand just use xmodmap -e "keycode stuff"

Here is some more info if you want to tweak it yourself/understand what is going on

This was tweaked for my liking, that way i can use "double brackets" for programming without any hassle whilst maintaining the ability to write á é í ó ú when needed
` for games that require Console Access whilst maintaining the ability to use ã ẽ ĩ õ ũ to write words like não

Worked here, thanks buddy!