help in /etc/passwd file

Shell Programming and Scripting
1

Hi all,

As all of us know that in /etc/passwd file the first field correspond to username
could any one tell me what is bin , damoen etc in the first field, and r they in
user field , what is nologin in the last column ?

root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin

2

bin and daemon are users. 'nologin' is precisely that; the effect is that nobody can login with the user bin or daemon. Which is a very good idea.

The following may help:

[Chapter 4] Users, Groups, and the Superuser

3

I have not created any bin or damoen users in my system so why these default
users are ? what is the purpose behind this ?

4

There are two types of user Unix/Linux system.
1:- System User (All the Daemons bin,system etc)
By default these users will have >0< 500 UID/GID(User ID and Group ID)
whenever you are installing the Unix/Linux in your system it will create automatically. Basically it need to run the Linux/Unix OS.

2: User specific User

During the Unix/Linux Installation That process will ask you to create the Root user and one Normal user. you can skip the Normal user creation but you can't skip the Root user creation.

Most of the User specific user is having >500 UID/GID
Only root is having 0 UID/GID

Hope it will help you to understand your question

Thanks
Sanjay Tripathi

5

thanks 4 ur useful info .

can i get some metarial on this topic bcz it seems to interesting ....