Linux OS Character maps
Character maps are programs you can use to find any special character and symbol from any font installed on your Linux system. You can find them and copy-paste, or you can find their Unicode codes and use those.GNOME

- Gucharmap in terminal.
- Applications ➢ Accessories ➢ Character Map.
References
- Gucharmap homepage on Gnome.org.
- Character Map information on Ubuntu.com
KDE Character Selector

You can access it in following ways:
- KCharSelect in terminal.
- Path is likely to be /usr/bin/kcharselect
Reference
- KCharSelect information on KDE.org.
Character map on Java

Features
Works anywhere where Java RE is installed. Can be resized. A single click adds character into text field. Text in this field is automatically copied to the system clipboard on each click. Author states that features are limited to make the application faster and simpler to learn and use.Download
- Java Character Map from Softpedia.