How to manage users accounts in Linux?
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
