Why don’t /etc/group and /etc/password match

groupusers

OK this is a basic question showing my ignorance of sysadmin matters…

Looking at the UNIX system I work on, my /etc/passwd entry says

my_name:x:uid:gid:comments:home directory:login shell

Then when I go and look at group 'gid' in /etc/group, I see

group_name:x:gid:some_other_name

So how come /etc/passwd thinks I am a member of the group, but /etc/group doesn't? Am I a member of the group or aren't I?

Is this normal? Your help would be appreciated.

Best Answer

/etc/passwd shows each user's primary group. /etc/group shows users who have a given group as one of their supplementary groups. For example, my username dan has the group dan as its primary group, so that is what appears in the group field in /etc/passwd. The user dan is also in the groups wheel, mailadmin and svn, so the entries for those groups in /etc/group list dan in the final field, which denotes group members.

Related Solutions

User created without a password behaves as if he had one

A user is created by default as a locked account. The field that should contain the password hash in /etc/shadow will contain !!. When an account is locked, that account is available to root only (root can su but logins aren't allowed). If you 'unlock' the account which simply removes the !! you will be allowed to change the password.

[root@test ~]# su - test
[test@test ~]$ passwd
Changing password for user test.
Changing password for test.
(current) UNIX password:
[test@test ~]$ exit
logout
[root@test ~]# passwd -u test
Unlocking password for user test.
passwd: Warning: unlocked password would be empty.
passwd: Unsafe operation (use -f to force)
[root@test ~]# passwd -u test -f
Unlocking password for user test.
passwd: Success
[root@test ~]# su - test
[test@test ~]$ passwd
Changing password for user test.
New password:

Why only one active group at a time

All groups are active at all times.

You can access any file that any of your groups can access. But when you create a new file/process it is created using your primary group, unless setgid or ACL defaults are in use.

Best Answer

Related Solutions

User created without a password behaves as if he had one

Why only one active group at a time

Related Question