Permissions are the unix way of controlling access to resources such as files, directories and devices and may be specified for an owner, group, or all users.

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setuid and setgid confusion

I'm trying to fully grasp the concept of setuid and setgid, and I'm not quite sure in what way permissions are actually elevated. Let me provide an example: Users userA (groups: userA groupA) userB ...
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1answer
4k views

How to mount USB stick on Debian Sid?

I've just installed Debian Sid on my computer but I cannot mount external USB drives as you can see in the image. Mounting failed Cannot mount "SENZATITOLO" Not authorized What should I ...
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1answer
1k views

How do I restore default owner of files in /var/ directory?

Accidentally in /var/ directory I ran chown root . -R;chgrp root . -R. Now services like mysql don't start. Is there a way to restore default owner and groups? If there is no way, what is the default ...
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2answers
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How to insert text into a root-owned file using sudo? [duplicate]

Possible Duplicate: Redirecting stdout to a file you don't have write permission on Running a command like sudo echo 'text' >> /file.txt fails with: bash: /file.txt: Permission ...
14
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1answer
15k views

Unable to delete file, even when running as root

I am in the process of migrating a machine from RHEL 4 to 5. Rather than actually do an upgrade we have created a new VM (both machines are in a cloud) and I am in the process of copying across data ...
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2answers
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I can't delete a file that I have write permissions for as a group member

$ touch testfile $ chmod g+w testfile $ sudo adduser user2 user1 $ stat -c'%a %A' testfile 664 -rw-rw-r-- $ su user2 Password: $ groups user2 user1 $ rm testfile rm: cannot remove `testfile': ...
8
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2answers
343 views

How is file ownership affected across different systems?

As I understand Unix file systems, any file on a unix system must belong to a group and a user of the said system. A file cannot belong to a group or user that does not exist on the system. From that ...
6
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1answer
2k views

Is it possible to disable file permissions on a ext3 or ext4 file-system?

Is it possible to disable file permissions on an ext3/4 file-system? Just wondering if it's possible to completely disable or ignore file permissions on a ext3 or ext4 file system. Perhaps a mounting ...
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2answers
884 views

encfs with expect access denied

If I execute script #!/usr/bin/expect set pass [lindex $argv 0] spawn encfs -v {CRIPT_DIR} {MNT_DIR} -o nonempty expect "*EncFS Password:*" send "$pass\r" expect eof expect script output: ...
3
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1answer
181 views

How to create a user with minimalistic permissions on OpenBSD?

I want to run the webbrowser (xxxterm) with a different user (XY) on an OpenBSD Desktop (different user from the one I use daily). I will reach the Browser with ssh -X in the local machine (or are ...
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2answers
6k views

CentOS - Issue with write permissions

I am running CentOS 6.4 and I have installed Wordpress on it. (along with LAMP) Now the problem is, that I cannot make any write changes to any files in the wordpress editor: eg. header.php, ...
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2answers
161 views

how to initialize `/etc/group`?

After editing /etc/group, How this update starts functioning without restarting the system in Unix? Is there any command we need to run?
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4answers
4k views

Permissions to deny SSH users from accessing other user's folders

I am currently running Fedora on a network computer, acting as a host to other users who will SSH into my terminal to do their work. However I realised that they are also able to access my /home ...
3
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3answers
218 views

Permissions for a submission script

I'm a TA for an introductory Python programming class (all work is done from the terminal), and I'm writing a project submission script. Ideally I want a directory setup like this: submissions/ ...
2
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3answers
494 views

lxc: running virtualbox inside a container

I've install virtualbox inside an lxc container. However when I try to start a VM I get the message: kernel driver not accessible (rc=1909) ....permission problem with /dev/vboxdrv. This obviously ...
2
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1answer
2k views

NAS box mounted via CIFS - problem with permissions

I'm running the latest version of Ubuntu, and have mounted a SMB share via a line in rc.local. The share mounts correctly, and I can browse files freely, create new files, and then delete them ...
2
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1answer
662 views

How to assign correct permissions to both webserver and svn?

I've an issue with files ownerships in unix. I have a drupal website and the "files" folder needs to be owned by "www-data" in order to let the users to upload files with php. However I'm now using ...
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3answers
2k views

Run Linux “motion” app as user

I'm trying to run Motion app on a Linux box. For various security reasons, I'd rather run it as regular user than sudo. However, when I run "service motion start" without the sudo in front, it says: ...
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3answers
844 views

Make web project writable by apache and other user

I am running ubuntu 12.04 LTS . To be able to view my web project in the browser I did the following: chown -R www-data:www-data /var/www/project Now I wanted to open the project in netbeans but it ...
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1answer
159 views

Shared partition permission management

I am willing to try a dual boot arch/lmde setup on my laptop next week, but I've ran into a problem: I want to have a shared data storage where my downloads, documents etc would reside and could be ...
10
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1answer
22k views

Preserve the permissions with rsync

Let's say I have a file a.txt in LINUX with permission of 0664. When I use rsync to copy the file to my Mac with rsync -r -t -v LINUX MAC, the file's permission becomes 0644. How can I keep the ...
8
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2answers
873 views

How to non-invasively test for write access to a file?

In a shell script, how do I easily and non-invasively test for write access to a file without actually attempting to modify the file? I could parse the output of stat, but that seems really complex, ...
8
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1answer
465 views

Cannot expand asterisk without proper permission

Can someone explain to me the following? $ ls -ld /temp/sit/build/ dr-xr-s--- 3 asdf qwer 4096 Jan 31 2012 /temp/sit/build/ $ ls -ld /temp/sit/build/* ls: /temp/sit/build/*: Permission denied So ...
7
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2answers
3k views

recursively change file permission but not directories?

I was doing a mass recursive change of permissions of some files that I had migrated to a unix system. I changed them to ug+rw, but then I found that I could not traverse subdirectories. I looked at ...
6
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6answers
273 views

File protection in Unix

Is there a way to protect a file in such a way that even root cannot delete it or rewrite it after creating it? I have a file which is created by root under /var/log/ and I want to restrict all users ...
6
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2answers
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Unable to delete file, even as root

I've got a file on remote machine (saying that, cause I don't know who the heck created it), that I've to remove. user@machine:~/folder$ ls lift_proto.db.lock.db And permissions are like this: ...
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5answers
263 views

Changing Unix group for files

I have a file that a colleague and I are editing together, on a Unix system. We are using Unix group permissions to edit it. We have one Unix group that we are both members of. Whenever I save the ...
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3answers
13k views

“echo 3 > /proc/sys/vm/drop_caches” - Permission denied as root

I am currently having some issues with the cache. It is a little too much right now so I wanted to clear it. I googled and found this little command: sync && echo 3 > ...
5
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2answers
1k views

How can I ensure only the root user have the right to halt/reboot the system?

CentOS Linux by default allows all users to have permission to "halt" & "reboot" the system by using the commands halt and reboot. How can I configure my system so that only the root user has the ...
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5answers
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How to setup password-less ssh with RSA keys

I am trying to setup a password-less SSH configuration between two machines and am having trouble. There are a ton of howtos out there that I have followed and have had no success. Here are ...
5
votes
2answers
365 views

Is it possible to represent the +X symbolic permission with an octal value?

Is it possible to represent the +X symbolic permission with an octal value? The chmod(1) man page says: execute/search only if the file is a directory or already has execute permission for some ...
5
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3answers
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Frustrating issue where neither cron nor su -c runs my job (permissions?)

Updated (and snipped) with more details below. I've set up a cron script and I'm trying to debug why it's not running. [Snipped context testing, which is all ok; see revision 2 for details] The ...
5
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1answer
4k views

mv file without write permission to the source file

I just realised that I can move a file that I do not own and don't have write permissions on. I have write permissions to the directory, so I am guessing that is why I could move it, but in this ...
5
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2answers
24k views

Why do I get an “rsync: failed to set times on … : Operation not permitted (1)” error on Ubuntu 10.10 with SME Server 7.4? [duplicate]

I am trying to cron an rsync via ssh between two fileservers that are running SME Server 7.4 and Ubuntu 10.10, respectively. The first rsync worked just fine (for reasons that I do not know), but now, ...
4
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2answers
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What are the permissions of a cron job?

When a cron job runs with what privilege does it execute? I'm not sure about that. Is it with the same privileges of the user that added it via crontab -e?
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2answers
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Can I allow users to chmod a file not owned by them?

I would like to allow users to chmod a file that is owned by root or some user that is not themselves. I have chmod'ed the file to 777 and I get "operation not permitted". I have added the user to the ...
4
votes
2answers
792 views

How can I backup a directory to NTFS while preserving Unix file attributes?

I want to make a backup of my home directory to an NTFS partition (an unfortunate limitation). However, when I last tried using just cp, the attributes (owner, etc) went away. How can I make a backup ...
4
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2answers
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How to set permissions in /sys/ permanent?

I'm starting X as a user and need to set my keyboard brightness in /sys/class/leds/asus\:\:kbd_backlight/brightness. The /sys/ directory gets recreated after reboot, so the permissions will reset too. ...
4
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6answers
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Transfer files using scp: permission denied

I try to transfer files from remote computer using ssh to my computer : scp My_file.txt user_id@server:/Home This should put My_file.txt in the home folder on my own computer, right? I get ...
4
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1answer
1k views

How to configure permissions to allow apache to securely have access to a file in a shared environment?

This is a follow up question from my previous, but I felt it might be more Linux based. http://serverfault.com/questions/414207/how-to-set-linux-permissions-to-allow-apache-to-have-access-to-a-file ...
3
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1answer
563 views

Write-only permission for a directory doesn't allow to rename (move) files inside?

In fact, I would like to ask more general question -- "what does write permission for a directory allow you to do exactly?" -- but let's approach it with a concrete example. It is a long question, if ...
3
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1answer
934 views

Help with giving group permissions to other user's files

I'm a linux beginner using Debian 7 and have created a new user (a website) with an htdocs directory like this: $ sudo adduser website $ sudo mkdir -p /home/website/htdocs $ sudo chown -R website ...
3
votes
1answer
4k views

File inheriting permission of directory it is copied in?

I have files created into my home directory with only user read permission (r-- --- ---). I want to copy this file to another directory /etc/test/ which has the folder permission of 744 (rwx r-- r--). ...
3
votes
1answer
2k views

permission denied for ptrace under GDB

I initially posted this question on StackOverflow, as a GDB problem. I didn't find a solution there, but they did help me find that it's a permissions problem, so I'm posting it here. I have set a ...
3
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1answer
871 views

How are file permissions applied to newly created files?

I have a directory that has the following permissions set: drwxr-s---. user group folder On the desktop, I access this folder and right click to create a new file call foo.txt. Then using the ...
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2answers
158 views

File permissions and saving

Let's say you open a file on which you have write permission. Meanwhile you change permissions and remove write permission while you still have the file open in some editor. What will happen if you ...
3
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2answers
2k views

Taking file ownership when file and directory is readable/writable

I got some files in directory: drwxrws-wt 2 me mygroup 4,0K 10.1. 12:34 . -rw-r----- 1 someone mygroup 10G 10.1. 11:22 someonesfile me and someone are regular users without supplementary ...
3
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2answers
966 views

A question about permissions of hierarchical directories

I have some directories, with following permissions: drwxr-xr-x 18 user1 root 4096 Oct 27 11:25 /home/test1/test2 drwxr-xr-x 24 user1 root 4096 Oct 21 08:38 /home/test1 drwxr-xr-x 492 root root 12288 ...
3
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3answers
334 views

Setting execution right to whole directory - is it good or bad idea?

I have a zip file containing lot of files and directories for a certain application which should be running on Linux. Some files needs to be set as executable, but the zip file format afaik does not ...
3
votes
2answers
4k views

how to chown mounted device?

When I plug in my external hard-drive when running KDE, it prompts me to mount the device (by clicking an icon, no sudo involved), and once I've done that I am the owner of the files. This is great. ...