I have been using the HTML5 profile of the EVE-NG and copy and paste is getting a bit annoying in Guacamole mode. It would be easier I can use a terminal. I am using Xubuntu and unfortunately, by default, the url telnet://<ip-addr>:<port> does not automatically open the built-in terminal and Firefox by default would just bark in error cannot open.
Open a new tab in Firefox and go to about:config as shown in Figure 1. Click on the Acept the Risk and Continue.
Enter the network.protocol-handler.expose.telnet to the field and make sure Boolean is selected then click the “+” button on the far right as shown in Figure 2.
Once added, change the Boolean from true to false as shown in Figure 3. Quit Firefox.
Copy or modify based on your preferred terminal the script below and save it in /bin/ or /usr/bin/.
sudo vim /bin/fftelnet
#!/bin/sh
address=`echo ${*##telnet://} | sed 's/:/ /g'`
# Adjust the terminal to your liking.
#xterm --tab -e "telnet $address"
#gnome-terminal --tab -e "telnet $address"
xfce4-terminal --tab -e "telnet $address"
Make the script executable
sudo chmod 755 /bin/fftelnet
Open Firefox again and trigger that telnet request again. In my case, it is from EVE-NG. You should get a prompt similar to Figure 4. Click on Choose button and locate the script from earlier.
Don’t forget to mark the Remember my choice for telnet links then click on Open link. At this point, every telnet link will open xfce4-terminal. Hope you’ll find this helpful.
Cheers!