Cedilla on ubuntu 18.04 64 bits with american keyboard

gistfile1.txt

Enabling cedilla and dead keys on kali linux

change: 
"cedilla" "Cedilla" "gtk20" "/usr/share/locale" "az:ca:co:fr:gv:oc:pt:sq:tr:wa"
to
"cedilla" "Cedilla" "gtk20" "/usr/share/locale" "az:ca:co:fr:gv:oc:pt:sq:tr:wa:en"
on these files:

/usr/lib/x86_64-linux-gnu/gtk-3.0/3.0.0/immodules.cache
/usr/lib/x86_64-linux-gnu/gtk-2.0/2.10.0/immodules.cache 

then:

sudo cp /usr/share/X11/locale/en_US.UTF-8/Compose /usr/share/X11/locale/en_US.UTF-8/Compose.bak
sed 's/ć/ç/g' < /usr/share/X11/locale/en_US.UTF-8/Compose | sed 's/Ć/Ç/g' > Compose
sudo mv Compose /usr/share/X11/locale/en_US.UTF-8/Compose

add
GTK_IM_MODULE=cedilla
QT_IM_MODULE=cedilla

to /etc/environment 
then

sudo locale-gen pt_BR.UTF-8
export LC_CTYPE=pt_BR.UTF-8