Adding user with graphical utility

Show the properties of tony user

[root@pc1 disk]# id tony

Uid=501 (tony) qid=501 (tony) qroup=501 (tony)

Add tow uses john and jhosen with different command with default properties

[root@pc1 disk]# adduser john

[root@pc1 disk]# useradd umer

Assigning password to john

[root@pc1 disk]# passwd john

Add a group

[root@pc1 disk]# groupadd cisco

Customizing users properties at the time of creating user

[-u uid ] [-g primary group] [-G secondary group] [ -c comments] [ -d home directory path ] [-s login shell ]

[root@pc1 disk]# usersadd -u 600 -g cisco -G saad -c "Manager" -d /etc/jonny -d /bin/sh jonny

Modify user properties with usermod command

[root@pc1 disk]# usemod -u 666 -s /bin/bash jonny

Delete a user jonny with his home directory

[root@pc1 disk]# userdel -r jonny

Delete a group cisco

[root@pc1 disk]# qroupdel cisco

All users information stored in /etc/passwd every user have a seven column line in this file

1-user name [ user authenticate at the time of login from the first column of /etc/passwd ]

2-password required [ x means users must required password if remove this x user can login without password]

3-uid [ 500 first user id 0 to 499 id's are reserved 0 for root user and remaining for services users ]

4-gid [ every user relate with any group which stored in /etc/group ]

5-comments [full name but it is not compulsory only for information ]

6-home directory path [ linux file system is read only for normal user only his home directory is with full

permission for normal user

7-login shell (/bin/bash, /bin/sh, /bin/tsh, /sbin/nologin) every user required a shell for login without shell user can never login at machine.

[root@pc1 disk]# gedit /etc/passwd

All groups stored in this file

[root@pc1 disk]# edit /etc/shadow

User password stored in this file

[root@pc1 disk]# gedit /etc/group