Bash manual says:
A login shell is one whose first character of argument zero is‘ -’, or one invoked with the --login option.
It defines a login shell in terms of the ways to start a login shell.
Alternatively, can a login shell be defined in terms of its intended purpose?
For example, can a login shell be defined as a shell which requires user to log in?
For example, in an interactive nonlogin bash shell, when I run
bash --login to create a bash login shell, I don't have to log in. Is it because my username and password are cached and reused implicitly, or simply it doesn't perform the job of login?
If a login shell doesn't necessarily have to perform log in, what is its intended purpose that can characterize a login shell from a nonlogin shell?