How do I use the command passwd to set a password for user the user01?

Question

Using command line, what do I type to create the password 123xyz for the user named user01?

Answer 1

Using

apropos password

provides an overview on possible command involving password.

In the list, you find:

passwd (1)           - change user password

This learns you that the command passwd can be used to change a password of a user.

Now,

man passwd

will show you the documentation ("man page") for that command, where you can learn how to change the password of user user01 to 123xyz.

Note that you must have administrator (aka "root") privileges to change another user's password. Thus, you will need to precede the passwd command with sudo in order to execute it with root privileges.