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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9
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5answers
3k views

Directory with +x permission, parents without it. When would this be useful?

Say I have a folder called folder in the following path: my_path = /a/b/c/d/e/folder and a file called file in that folder. Then, say I run this command to remove group permissions under /a/ > ...
6
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5answers
1k views

Making a directory protected from 'rm -rf'

I just lost some data in folder A which was inside folder B after doing rm -rf B. Before I could realize what have I done, it was all over. Now a lesson is learnt, I wish to make some of my folder ...
7
votes
2answers
8k views

Make all files under a directory read-only without changing permissions?

First, some background: /dev/md1 is a RAID-0 array serving as primary file store. It is mounted to /var/smb. /dev/md2 is another RAID-0 array storing backup snapshots taken from /dev/md1. It is ...
18
votes
5answers
745 views

Find files that a user can write, efficiently with minimal process creation

I am root. I would like to know whether a non-root user has write access to some files - thousands of them. How to do it efficiently while avoiding process creation?
10
votes
4answers
55k views

VSFTPD, 553 Could not create file. - permissions?

I've set up VSFTPD on Amazon EC2, with the Amazon Linux AMI. I created a user and can now succesfully connect via ftp. However, if I try to upload something I get the error message "553 Could not ...
7
votes
3answers
8k views

bash: /dev/stderr: Permission denied

After upgrading to a new release version, my bash scripts start spitting errors: bash: /dev/stderr: Permission denied in previous versions Bash would internally recognize those file names (which is ...
5
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4answers
24k views

What are the settings to correct vsftpd “500 OOPS: cannot change directory” error?

My question is what settings do I need to change and/or commands to run to allow me to log into my vsftpd system? I am getting this error, when I login using ftp instead of sftp: Name ...
5
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2answers
3k views

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 ...
3
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2answers
1k views

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 ...
2
votes
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 ...
2
votes
2answers
5k views

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
votes
1answer
18k 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 ...
12
votes
1answer
26k 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 ...
11
votes
2answers
5k views

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
votes
2answers
359 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 ...
7
votes
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 ...
5
votes
1answer
1k views

Writing raw images safely to USB sticks

Trying lots of different linux, on all kinds of hardware I find my self typing commands like this quite often: sudo dd if=xubuntu-13.10-desktop-amd64.iso of=/dev/sdc bs=10240 Needless to say, ...
5
votes
3answers
5k views

find files which have a higher permission than xxx

I want to find all files which have a higher permission than e.g. 640. Perhaps this would work with a find and exec command. But my knowledge isn't sufficient for such a task.
4
votes
2answers
942 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
votes
1answer
194 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 ...
3
votes
2answers
7k 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, ...
3
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2answers
175 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?
3
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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
votes
3answers
228 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
4k views

Allow a user to view the home directory of other users via sudo

I am new to system administration. We have a lab set up where we have a server and client machines. The client machines have LDAP users which has the work area for all the users in the centralized ...
2
votes
3answers
600 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
votes
1answer
3k 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
votes
1answer
682 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 ...
1
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3answers
39 views

To Rsync files where permission denied

I want to find those files which I cannot copy to another location such that I could do Rsync. I have an external HDD and my system´s HDD. The external HDD has files which my system is missing. I ...
1
vote
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: ...
1
vote
3answers
1k 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 ...
1
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1answer
169 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 ...
8
votes
2answers
1k 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
votes
1answer
588 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 ...
8
votes
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
votes
3answers
16k 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 > ...
6
votes
7answers
306 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
votes
2answers
17k views

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: ...
6
votes
5answers
268 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 ...
5
votes
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 ...
5
votes
5answers
2k views

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
415 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
votes
3answers
2k views

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
votes
1answer
5k 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
votes
2answers
26k 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
votes
2answers
13k views

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?
4
votes
2answers
855 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
votes
2answers
2k views

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
votes
6answers
36k views

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
votes
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 ...