(A tab character might not be a wise choice, depending on what kinds of computers you'll be logging in from.) There are many software packages that can generate random passwords for you; search the Internet for these utilities.
Removing users is not difficult at all.
Disabling an account might be useful if the user doesn't play by the rules you've set up on your system, or if they've exported a very large copy of xeyes(1) to logic pro x windows 7 your X desktop.In order to change your own password, you would type: passwd Changing password for chris Old password: Enter the new password (minumum of 5, maximum of 127 characters) Please use a combination of upper and lower case letters and numbers.At this point, it might be a good idea to use the pwck and grpck commands to verify that the changes you've made are consistent.To change your shell, use chsh: chsh Password: Changing the login shell for chris Enter the new value, or press return for the default Login Shell /bin/bash: After entering your password, enter the full path to the new shell.If your new user comes from a Unix background, they may be familiar with a different shell.Also, remember that once you've deleted the user, all of that user's password information is gone permanently.As the names indicate, halt will immediately halt the operating system, and reboot will reboot the system.It is up to you to edit /etc/group to add users to a specific group.Control, c and start over.The group file lists all the groups and who is in each.You might want to place the new user into a different group, but it is not recommended unless you know what you're doing.This was once the case, but was halted long ago for security reasons.
If you'd wanted to remove the home directory as well, you would instead use this command: # userdel -r jellyd Temporarily disabling an account will be covered in the next section on passwords, since a temporary change involves changing the user's password.
Removing a user is a simple matter of deleting all of the entries that exist for that user.
The root user can also change any user's shell by running chsh with a username as the argument.The most basic use of shutdown to power down the computer is: # shutdown -h now In this case, we are not going to send a custom message to the users; they will see shutdown's default message.With the exception of chfn, chsh, and passwd, these programs are generally only run as root, and are therefore located in /usr/sbin.First, we'll add a new user to the /etc/passwd(5 /etc/shadow(5 and /etc/group(5) files.Choosing a Password : Having a secure password is the first line of defense against getting cracked.Then, you are prompted to enter the new password.Finally, the file that ultimately controls every aspect of startup and shutdown is the /etc/inittab(5) file.The second way of shutting down or powering off the computer is to use the halt(8) and reboot(8) commands.