All about Unix groups and access control.

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0
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2answers
124 views

Change/Create permissions for a folder

How can I create (if the folder is new) or change (if the folder was already existent) permissions for a folder? In particular, I want to create a subdirectory in /etc/bind/ where I can put the ...
4
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3answers
774 views

how to login as a member of specific group

i want to login as a member of non primary group to create files whose owner as a member of non primary group of current user. -rwxr-xr-x 2 gowtham gowtham 4096 Sep 5 14:48 defaultNewFile ...
1
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1answer
1k views

Accessing another user's files

I have a file "abc" with permissions 440 .The owner of this file is "root" and the group of this file is "groupabc" . I have a user "user1" .Is their anyway I can see the contents of files "abc" using ...
1
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2answers
3k views

wireshark: Couldn't run /usr/sbin/dumpcap in child process [duplicate]

Possible Duplicate: How to add write permissions for a group? When I run Wireshark, It shows the following message: Couldn't run /usr/sbin/dumpcap in child process: Permission denied Are ...
6
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1answer
3k views

addgroup vs groupadd

I happen to know there is a slight difference between adduser and useradd. (i.e., adduser has additional features to useradd, such as creating a home directory.) Then what is the relation between ...
4
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2answers
1k views

Why don't /etc/group and /etc/password match?

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 ...
1
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1answer
7k views

Error message id: cannot find name for group ID after logging in

BACKGROUND Trevor logs into his account on ssh://foobar.university.edu as one of the developers on the box, and he gets the message: id: cannot find name for group ID 131 Trevor then checks this ...
2
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1answer
376 views

Adding Windows user to Linux group; possible?

I have a NAS that runs on Linux and I connect to it from my Windows desktop. I noticed that all directory in that drive belongs to user 'root' and group 'root'. That effectively denies me the right to ...
2
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1answer
2k views

How to ensure that anonymous FTP has been disabled on a Solaris 10 system?

What line in which configuration files in the /etc/ftpd directory do I have to check to ensure that anonymous FTP has been disabled? From my understanding now, to ensure that anonymous FTP is ...
1
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1answer
171 views

How to disable messages in unix if mesg and chgrp not allowed?

This is one of my questions for my exam .. We are not supposed to use mesg y/n for this but we should effectively avoid mesgs along with the problem of not being able to change groups.
5
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3answers
1k views

Can't read a file although it's in my group and permissions for group read are set

I encounter a strange problem on a unix/linux machine: I'm member of a group, let's call it group A and a certain file (which has a different owner) belongs to group A as well. The permissions of ...
2
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0answers
212 views

Samba: system group mapping

I have w2008R2 PDC and Linux server with samba and winbind. Now I'd like to add some domain users to Unix adm group in AD. Let's say I have adm group defined in AD, and every user from this group ...
1
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1answer
181 views

How to filter group membership from the ldap server?

Context : We have a Ubuntu 12.04 with authentication done on a ldap server. Unfortunately, one (ldap) user belongs to a (ldap) group named "admin". I know there is the option ...
2
votes
1answer
237 views

Why does newgrp change my PS1 and how to prevent it?

I have a customized PS1 to show several parameters. When I switch to a different group using newgrp, it switched my PS1 to default ($) and that is annoying. The default remains even when I switch ...
0
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1answer
3k views

Full access by group user of /var/www/html [duplicate]

Possible Duplicate: How to add write permissions for a group? On Centos 6 I'm trying to give full access to make and delete by the user mitch for /var/www/http. I did addgroup www and then ...
6
votes
1answer
5k views

Group within group file permissions

I tried finding this on here, but couldn't so sorry if it's a duplicate. Say I have 2 groups and a user: group1, group2, user1 with the following structure: group1 is a member of group 2, user1 is a ...
3
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1answer
211 views

In my secure log there is a new group added that Im unsure about after adding semanage

I installed semanage onto my CentOS 6.2 box and I was going through my secure log after the install and noticed this entry: Aug 31 22:12:17 xxxx groupadd[12929]: group added to /etc/group: ...
9
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1answer
2k views

In /etc/group what is the meaning of the second field?

A sample /etc/group file contains the following entries: root:*:0: adm:!:4:logcheck antoine:x:1000: The man pages I've read (Debian & OSX) says the second field is to store a group password. ...
1
vote
1answer
423 views

Group Permission on public_html [duplicate]

Possible Duplicate: Permissions: What's the right way to give Apache more user permissions? Before I knew better, I used /home/someuser/public_html/scripts as a place from which shared ...
2
votes
1answer
4k views

Why this error: “cannot create directory `foo': Permission denied”

I get this error when I try creating a directory: [rex <03:57 PM> /var/tmp/pb82]$ mkdir foo mkdir: cannot create directory `foo': Permission denied But doesn't the following output indicate ...
2
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3answers
1k views

Limited SSH user on Ubuntu 12

I'm running Minecraft on a server. How can I give my friend SSH access just to the minecraft folder (a root folder), the screen command, and some ports?
6
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3answers
2k views

What does it mean to be in group 0?

Several users in a system I inherited have their group set to 0 in /etc/passwd. What does that mean? Do they essentially get full root privileges? The system is running CentOS 5, and the users ...
3
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3answers
6k views

What does GID mean?

What does GID actually mean? I have Googled it and this is what linux.about.com said: Group identification number for the process. Valid group numbers are given in /etc/group, and in the ...
1
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2answers
263 views

How to maintain file ownership when running 'yum update'

I'm running CentOS 6.2 and installed nginx as root. After the install I changed the owner and group of the install to it's own user and group to keep thing a bit more secure. I logged in as root and ...
4
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2answers
422 views

Group ID 501 cannot be found

A file in a directory has a Group ID "501" After checking /etc/group, Group ID "501" was not found how is that possible ?
2
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1answer
2k views

How do I set permissions for a directory so that files and directories created under it maintain group write permissions? [duplicate]

Possible Duplicate: Make all new files in a directory accessible to a group I have a directory in which collaborative files / directories are stored. Say directory abc is owned by root and ...
2
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5answers
9k views

What is the command for listing all users who are members of the admin group?

I am looking for the name of the superusers list on Fedora. (On Ubuntu is seems to be "sudo".) I want to add one of the users to the superusers list. The groups command only lists the groups of the ...
3
votes
3answers
214 views

When adding a user to a new group when does the user group permissions become active when its a /nologin user?

I have a service level account to run my webserver, and this user is setup with /sbin/nologin. Normally when you add a user to a group you must logout and login to use the new group permissions. ...
0
votes
1answer
226 views

Incompatible group permissions in Linux - Is it a bug? [duplicate]

Possible Duplicate: How to apply changes of newly added user groups without needing to reboot? I am on Ubuntu 11.04. I am creating another user and placing an existing user in the group of ...
1
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0answers
298 views

Adding a second user to a system group? [closed]

I am trying to get around a permission issue I am having. The only reasonable option (other than ACL) is to add the user that needs access to the system group of the user that has access. Yes, the ...
5
votes
1answer
90 views

assigning files of a group to another one

I want to delete a group using groupdel command, but before doing this I want to assign all files belonging to this group to another one is there a way to do this? I know that I can use find / -gid ...
12
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3answers
29k views

Change gid of a specific group

I'd like to change group id of a specific group. There are so may solution for changing the gid of a file or directories. But that's not what I want. Is there a way to do that?
62
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5answers
85k views

How do I remove a user from a group?

Which command should I use to remove a user from a group in Debian? When adding a user to a group, it can be done with: usermod -a -G group user However, I could not find a similar command ...
7
votes
2answers
3k views

linux permission, group member cannot write even with write permission

The logged in user is a member of a group that has a write permission on a folder. But when this user is trying to write something, "permission is denied". The log below summarizes the question: ...
5
votes
5answers
1k views

Why is it recommended to create a group and user for some applications?

Most of the time, when installing a program from source it is recommended to create a new user and a new group and give /usr/local/<myapp> the recently created user and group ownership. Why is ...
3
votes
2answers
2k views

Using umask to set group permissions

A long time ago an old friend showed me a way to use an octal or hex umask with a group I think using /etc/profile. I'm not sure. I'm trying to create group on Debian so that every member of that ...
3
votes
3answers
532 views

Escaping argument in bash script?

I'm writing a bash script wherein I want to check that one of the arguments passed to it is a valid group. I have the line if [ `grep -c -e '\b$2\b' /etc/group` -eq 0 ]; then echo "Error: $2 is ...
2
votes
2answers
611 views

Can I share a folder inside my home directory with another user?

Can I share a folder inside my home directory with another user? I have two users on a system, agent and daemon. An external server connects as agent and rsyncs files to ~agent/incoming I want ...
16
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2answers
36k views

How can I change a user's default group in Linux?

Being new to Linux administration, I'm a little confused about the following commands: useradd usermod groupadd groupmod I've just finished reading the user administration book in the Linux/Unix ...
7
votes
1answer
556 views

What is the purpose of `/etc/group-`

On a standard Linux distribution (e.g. Ubuntu) there is usually /etc/group and /etc/group-, where the second one is only readable by root. man group only describes /etc/group. Thus my question: What ...
1
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2answers
2k views

Can't access Apache log folder

I want to see apache log file. This is what I tried: I granted most all permissions to apache2 folder. hieund@hieund:/var/log$ sudo chmod a+rw apache2/* But I can't cd to it. So I add my user to ...
2
votes
1answer
8k views

Changing user and group ID system wide (including file system attributes)?

(this question possibly related to Linux: simulating/masking user ownership upon mount of 'external' partitions? - Stack Overflow) I typically use Ubuntu (currently 11.04) as my desktop OS; let's say ...
0
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2answers
93 views

How to write in directory out of home?

I have my Apache server running in the /srv/http/ directory. I changed the group of it to httpadmin and then added my user to that group. Then, I changed the permissions of that directory to ...
6
votes
1answer
6k views

what is 'nogroup' group's purpose

When I list al groups I see one called 'nogroup'. What is this for? Is it supposed to be least privileged one or something? I'm using ubuntu 11.04.
2
votes
2answers
665 views

su user fails with “grep: /var/cpanel/users/user: Permission denied”

I just did something pretty simple. Given a user user, I modified his user id, primary group's id, and added him to a new group in order to make my server use the same uid and gid as another server ...
2
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3answers
314 views

Group information reported wrong for a specific user

I have a problem on a server I manage. An account (specifically, my account) does not seem to have the correct groups. I think the problem is most easily demonstrated by looking at the following ...
4
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2answers
2k views

Problem while running “newgrp” command in script

I want to change the working group in my script. So I wrote a line newgrp test_grp1 in my script. But my script is automatically exited after running this line. Are there any solution to overcome this ...
15
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2answers
6k views

How to apply changes of newly added user groups without needing to reboot?

Assume I'm logged in with user takpar: takpar@skyspace:/$ As root, I've added takpar as a member of group webdev using: # usermod -a -G webdev takpar But it seems it has not been applied. because ...
8
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2answers
6k views

GID, current, primary, supplementary, effective and real group IDs?

The following links discuss these concepts in different contexts. I have read their definitions, but I still can't tell how they are related, or if some of them are just the same. Current group ID ...
4
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1answer
486 views

Why do I need to use newgrp or su (or logout and login again) to have new group memberships applied?

What is it that makes new group membership require a new login (or new login shell as started by su or newgrp) to be visible? Just running another bash (or whatever other shell) instance with --login ...