What is /dev/random?
In Unix-like operating systems, /dev/random, /dev/urandom and /dev/arandom are special files that serve as pseudorandom number generators. They allow access to environmental noise collected from device drivers and other sources.
Here is an example where we generate a password with 10 symbols
</dev/urandom tr -dc '12345!@#$%qwertQWERTasdfgASDFGzxcvbZXCVB' | head -c10; echo ""
You can edit the symbols and the length for the generated password. -c10 is the lenght.