How can I check installed program versions in terminal. Is there any command for that, for example ver or something similar?
The way how to know version of an installed package varies for different programs. Usually
can be used to know it. It is better to see
man application_name and search which is the command line switch to know the version.
If you installed any package using
apt, to see the version you can try
apt-cache policy package_name
In few cases the version can be found in
application_name --help. For example
In few very little case
application_name -v also gives you version.