How to analyze the password of new users in Linux, and how to analyze the linux Password

How to analyze the password of new users in Linux, and how to analyze the linux Password

When we create a user in Linux, if no password is set, the password is unknown, and it is not an empty password, we can use passwd to modify and find that no matter what we input or do not input, it does not work, and that this user cannot be logged in, of course, there is one case, the root user is used for su.

Of course, the password problem is also very simple. As long as we ensure that useradd and passwd appear in pairs, there is certainly no problem. The biggest misunderstanding is that we will think that there is no password without a password, and we can simply press enter, but this is not the case.