Where are gedit's preferences?

if you are using GNOME 3, you can access the preferences via the top menu.

you should have "activities" on the top left corner of your screen. on the right side of activities, you will have gedit. click on it, and you should see the preferences.

I'm not sure how to get preferences back in your menus, but you can use gsettings to display line numbers. Enter this command into the terminal:

gsettings set org.gnome.gedit.preferences.editor display-line-numbers true

In case you need to change other settings for gedit, you can use this command to find quite a few that are available: (thanks to this answer)

gsettings list-recursively | grep -i gedit

To get the preferences entry back to the edit menu perform the following command in a terminal:

gsettings set org.gnome.settings-daemon.plugins.xsettings overrides '@a{sv} {"Gtk/ShellShowsAppMenu": <int32 0>}'

The problem results from Gnome3 putting the preferences menu entry to the top menu.