In /usr/share/applications
there will be a .desktop
file for the app. This may not have the most obvious name, but you will be able to figure it out by trial and error...
Open the .desktop
file and look for the first line that starts with
Exec=
After =
is the command the launcher uses to start the program, so you can use it in a terminal.
You may be able to simplify the command, for example, if it is a path, but the application is in your path, you can type only the name of the application. Or, your system might even have a shortcut to it.
Examples
In libreoffice-calc.desktop
I find the line
Exec=libreoffice --calc
Typing libreoffice --calc
launches libreoffice calc
In python2.7.desktop
I find
Exec=/usr/bin/python2.7
But I can launch it with only python
because:
$ file $(which python)
/usr/bin/python: symbolic link to python2.7
In the file telegram.desktop
I find
Exec=/opt/telegram/Telegram
But I can launch it only with Telegram
because I have added /opt/telegram
to my path:
$ echo $PATH
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/opt/telegram:/opt/lks-indicator:/snap/bin
(See how to add directories to your path here)