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Showing posts from February, 2012

SAMBA client in Linux with GUI

We can connect samba server with GUI mode as like windows machine in Linux.

Run Application will be used to access samba server in Linux with GUI.

Alt+F2 used to open Run Application window.

It looks as follows.


Just type smb://{samba server address} and hit Enter.

Ex.

smb://10.1.1.1

This will open your samba share window. Give password if it asks.

Users and Groups in Linux - 7

gshadow The gshadow is group password file, It is used for encrypted passwords of group. It is also as like shadow file. It is located at /etc/gshadow.The normal user can's view this and root user only can view and edit.

Location : /etc/gshadow

Fields : 


1 - Group Name : It is name of group.

2 - Encrypted Password : It is current hash of the group's encrypted password.  The encrypted password consists of characters from the 64-character alphabet a thru z, A thru Z, 0 thru 9, \. and /.  If in encrypted password edited with ! or *, the user will not be able to use a unix password to log in.

3 - Administrators : The list of  administrative users separated by comma. This will be done with "gpasswd -A"

4 - Members : The list of members separated by comma.

* Use man pages for more help.

Users and Groups in Linux - 6

group The group file is as like passwd file. passwd is used to store user account information as like group file is used to store group information. It is located at /etc/group. It mainly used for store group name and their user name. Normal user can view this file. But only the root user can edit this.

Location : /etc/group

Fields : 


1 - GroupName : It is name of group.

2 - Password : Normally password is not used in group. It can store encrypted password as like shadow, here it'll be in gshadow. This is useful to implement privileged groups.

3 - GroupId (GID) : It is a unique id for the group. Each user have group id. We can see this at /etc/passwd file.

4 - Group List: This is list of user under this group, means member of this group. Each user separated by comma",".


* Use man pages for more help.

Users and Groups in Linux - 5

shadow The shadow file is mainly used for store Linux User's login passwords as encrypted. It located in /etc/shadow. It's encrypted passwords. So we can't use this passwords straightly for login. The root user only can access this file anything view are edit. Other user don't have permission to view this file.

Location : /etc/shadow

Fields : 


1 - UserName : It is name of user which we created or superuser or system user.

2 - Encrypted Password : It is current hash of the user's encrypted password.

3 - Last Password Change : It is date of last password changed from 1 Jan 1970. It is UNIX time format (Epoch). You can know more about it here. The encrypted password consists of 13 to 24 characters from the 64 characters alphabet a thru z, A thru Z, 0 thru 9, \. and /. Optionally it can start with a "$" character. This means the encrypted password was generated using another (not DES) algorithm. For example if it starts with "$1$" it means the MD5-based …

Users and Groups in Linux - 4

passwd The passwd file is used for store Linux User account information. And it'll be located in /etc/passwd. It contains root and system user accounts information also. So if any wrong changes happened it affect full Linux system. It only have read permission for all user and have edit permission for root.


Location : /etc/passwd

Fields : 


1 - UserName : It is name of user which we created or superuser or system user. Here the first "kumar" is user name. Linux allows user name will be 1 to 32 characters.

2 - x : It is location of password file. Here x point out /etc/shadow.

3 - UserID (UID) : It is a unique number for user. It'll be create at the time of user creation. 0 for super user (root). 1 - 500 for system users. 501 to 60000 for normal users and 60001 to 65535 for duplicate user.

4 - GroupID (GID) : It is a unique number for group. It'll be create at the time of user creation. 0 for super user (root). 1 - 500 for system users. 501 to 60000 for normal users and 6…

Users and Groups in Linux - 3

How to create user without group ?
Up to i searched and tried, we can't create user without group. We can only create a user with already created group.


How to create user with already created group ?
We can create a user with already created group with "-g" or "-G" option with "useradd" command.
Ex.
useradd -g group1 user1
     //user1 will be create in group1 and group1 will be primary user of user1
useradd -G group1 user1
     //user1 will be create in group1 and group1 will be secondary user of user1


How to create user without password ?
We can create a user without password by "passwd" command with "-d" option.
Ex.
useradd test
passwsd -d test


How to create user with more groups ?
When we create user, the primary group will be creat at same time or we want to mention group name with "-g" or "-G" option. We can mention multiple groups while create new user. And also we cam mention with "usermod" comm…

Users and Groups in Linux - 2

Delete user

userdel command used for delete user. We can do it with root user.

Ex.
#userdel -f username
     // -f for delete user home directory.

Delete group

groupdel command used for delete group. We can use it with root user.


Ex.
#groupdel groupname

Files in Linux for User and Group
passwdshadowgroupgshadow
     passwd
          The passwd file is used for store Linux User account information. And it'll be located in /etc/passwd. It contains root and system user accounts information also. So if any wrong changes happened it affect full Linux system. It only have read permission for all user and have edit permission for root.

     shadow
          The shadow file is mainly used for store Linux User's login passwords as encrypted. It located in /etc/shadow. It's encrypted passwords. So we can't use this passwords straightly for login. The root user only can access this file anything view are edit. Other user don't have permission to view this file.

group
          The …

Users and Groups in Linux - 1

Users :
Linux is Multi user environment. The users are those who can access the operating system resources with proper permissions as defined already.

Types of users :
I.   System Users
II.  Root User
III. Normal Users

I. System Users - They are default user in linux for some system process and service.
II. Root User - Root user is administrator of Linux System. He have all rights in machine. So should be very carefully with root user. Unknown mistakes may crash the system.
III. Normal Users - They are created by us for some reasons. They are limited users.

Groups : 
Groups are Logical experiences for tying users together. Normally groups are used to share files and permissions.

Types of groups :
I.   System Groups
II.  Root Group
III. Normal Groups

I.   System Groups - They are default groups in linux for some system process and services.
II.  Root Group - Root group is administrator group of Linux System.
III. Normal Groups - They are created by us for some reasons. They are …