Sponsored Content
Full Discussion: Unix File Permissions
Top Forums UNIX for Beginners Questions & Answers Answers to Frequently Asked Questions Tips and Tutorials Unix File Permissions Post 73755 by Perderabo on Friday 3rd of June 2005 07:20:56 PM
Old 06-03-2005
Set GID Bit on Directories

We briefly mentioned that files have a user and group associated with them. Originally, it was just the user and group of whoever created them. But originally, a user could be in only one group at a time. BSD introduced the concept that a user could be in multiple groups simutaneously. So in BSD, which group was used? BSD decided to use the group of the directory that contained the newly created file.

Many modern versions of unix try to have it both ways. A newly created file gets the group of the user unless the directory has the setgid bit. In that case, the newly created file gets the group of the directory.

And there is an exception to that! Changing the owner or group of a file has security concerns. For that reason, some versions of unix will, optionally, prohibit a user other than root from changing the owner of a file. Additionally, a user is prohibited from changing the group of a file unless he is a member of the new group. This restriction will override the setgid bit on a directory if needed.
These 3 Users Gave Thanks to Perderabo For This Post:
 

8 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Unix permissions

I am currently running jsp pages on unix server. At the top of my page is the import statement: <%@ page import="survey.*"%>. This imports the survey folder which i have placed in the same directory as my jsp page- jsp-servlet. However, when i try to run the page, its gives me an error saying that... (2 Replies)
Discussion started by: moukoko
2 Replies

2. UNIX for Advanced & Expert Users

UNIX File Permissions

Hello, What does the following mean in terms of file permissions. -rw-rwSrw- 1 owner group 999 May 25 2004 file_name What does the "S" stand for. Thanks in advance for your input. :) (3 Replies)
Discussion started by: jerardfjay
3 Replies

3. Solaris

Unix permissions

Is anyone aware of a tool that would produce a report or an extract file of all users, the files thry are allowed to access and their associated rights permitted (Read,Write etc.) (0 Replies)
Discussion started by: mobershaw
0 Replies

4. UNIX for Dummies Questions & Answers

Unix permissions for a newbie

Okay, this may turn out to be something quite simple, but I haven't found the answer so far: 1) Is it possible to retrieve a list of user(ID) file permissions? and then... 2) What is the most efficient way to create an alert/error message when/if those file permissions are denied? ... (2 Replies)
Discussion started by: hades1013
2 Replies

5. Shell Programming and Scripting

Unix File Permissions

I want to change one of my Dir permissions to drwx--S--- Can you tell me which number i have to use. Thanks in Advance (4 Replies)
Discussion started by: veeru
4 Replies

6. UNIX for Dummies Questions & Answers

Unix Permissions

We have a user group ‘norkgrp’ which is having 2 users ‘norkadm’ and ‘oracle’. Further we have a directory ‘fstf_blobs’ where ‘norkadm’ is the owner and ‘norkgrp’ is the group owner. The permission is set as 770. $ ls -lrt drwxrwx--- 2 norkadm norkgrp 1024 Jun 24 05:03 fstf_blobs We... (5 Replies)
Discussion started by: varunrbs
5 Replies

7. Solaris

Unix file, folder permissions, security auditing tools.

I want to periodically check if ASCII password/config files on Unix have 400 or 600 access. Folders and files are owned by designated group and user. Folders and Files do not have world write access. Are there any tools/scripts available for this kind of auditing that I can use on Solaris? (7 Replies)
Discussion started by: kchinnam
7 Replies

8. Shell Programming and Scripting

ksh; Change file permissions, update file, change permissions back?

Hi, I am creating a ksh script to search for a string of text inside files within a directory tree. Some of these file are going to be read/execute only. I know to use chmod to change the permissions of the file, but I want to preserve the original permissions after writing to the file. How can I... (3 Replies)
Discussion started by: right_coaster
3 Replies
luseradd(8)						      System Manager's Manual						       luseradd(8)

NAME
luseradd - Add an user SYNOPSIS
luseradd [OPTION]... user DESCRIPTION
Adds an user with name user. OPTIONS
-c, --gecos=gecos Set the GECOS field to gecos. The GECOS field is traditionally used to store user's real name and other information. -d, --directory=directory Set user's home directory to directory. If this option is not present, a default specified by libuser configuration is used. -g, --gid=group Set user's primary group to group. group can either be a group ID of an existing group, or a group name; if group is a group name and the group does not exist, it is created. If the --gid option is not specified, the default group name is user. -i, --interactive Ask all questions when connecting to the user database, even if default answers are set up in libuser configuration. -k, --skeleton=directory Populate the newly created user's home directory with a copy of directory. If this option is not present, a default directory spec- ified by libuser configuration, or /etc/skel if libuser configuration does not specify a default, is used. -M, --nocreatehome Don't create a home directory and a mail spool for the newly created user. -n, --nocreategroup If a group is not specified using -g, use group name "users" instead of user. Note that despite the name of the option, the group will still be created if it does not exist. -P, --plainpassword=password Set user's password to password. Note that the password can be viewed while running luseradd using tools such as ps(1). -p, --password=encrypted Set user's password to the password represented by the hash encrypted. Note that the hash can be viewed while running luseradd using tools such as ps(1). -r, --reserved The user is a system user. Users that are not marked as system user usually have automatically selected user IDs above a certain value (500 by default). This information is also passed to the libuser backends. This option implies the -M option. -s, --shell=shell Set user's login shell to shell. If this option is not present, a default specified by libuser configuration is used. -u, --uid=uid Use user ID uid for the newly created user. An user ID is selected automatically if this option is not present. EXIT STATUS
The exit status is 0 on success, nonzero on error. libuser Jan 12 2005 luseradd(8)
All times are GMT -4. The time now is 02:11 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy