How to enter a tab character in gedit if replacement with spaces is set up?

You can insert a literal Tab character in gedit by using the GNOME Unicode input mode:

Ctrl + Shift + U

and then enter 9 followed by Enter. The horizontal tab character is Unicode code point U+0009. This will insert a tab regardless of your preferences to expand tabs or not.

You can create shortcuts to quickly change this setting:

gsettings set org.gnome.gedit.preferences.editor insert-spaces false

Install a plugin for gedit

1. Clone the repository git://git.gitano.org.uk/personal/liw/makefiletab3.git

   mkdir -p ~/src
   cd src
   git clone git://git.gitano.org.uk/personal/liw/makefiletab3.git
   

2. Create the plugin folder for gedit

   mkdir -p ~/.local/share/gedit/plugins
   

3. Create a symbolic link

   ln -s ~/src/makefiletab3 ~/.local/share/gedit/plugins/makefiletab3
   

4. Change the Python version in makefiletab3.plugin

   Open the file

   nano ~/.local/share/gedit/plugins/makefiletab3/makefiletab3.plugin
   

   and replace

   Loader=python
   

   with

   Loader=python3
   

5. Restart gedit and activate the plugin