check correct syntax and file format of ‘/etc/passwd’ and users existence

pwck

Delete a user ( ‘-r’ eliminates home directory)

userdel -r user1

Set deadline for user password

chage -E 2008-12-31 user_name

Change a user’s attributes

usermod -c "User FTP" -g system -d /ftp/user1 -s /bin/nologin user1

Create a new user belongs “admin” group called ‘user1′

useradd -c "Name Surname " -g admin -d /home/user1 -s /bin/bash user1

There is a simpler command too…

useradd user1

Rename a group

groupmod -n new_group_name old_group_name

System info about a user. Try: finger root. An admin needs it all the time

finger user_name

#finger root
Login: root                             Name: root
Directory: /root                        Shell: /bin/bash
Last login Tue Nov 27 20:19 (IST) on tty1
No mail.
No Plan.

To get into single user mode in Linux, stop the boot at grub then edit the kernal you want to boot and add the word ’single’ at the end. For example ‘kernel /vmlinuz-2.6.21-1.3194.fc7 ro root=LABEL=/ rhgb quiet single’(your line may be different)

Disabling startup login prompt for password

• Click Start and Run
• Type “Control Userpasswords2″ and press enter.
• Uncheck the box for “Users must enter a user name and password to use this computer.”
• Click Apply and Ok.

[tags]windows,xp,password,user,boot,startup,prompt[/tags]