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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2
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208 views

How to change permission of anonymous pipe?

I've the script which loads the SSH key from the variable (as part of script in CI environment) in order to not keep the private file in the public repository, however ssh-add complains about the ...
2
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3answers
75 views

Change files with Editor that need sudo permissions

I want to change files with KomodoEdit, that need sudo permissions. I cant start KomodoEdit with sudo tho (for whatever reason). Can I somehow grant Komodo permission to edit those files (in ...
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1answer
3k views

permission denied when executing binary despite “rwx” privilege and root user

I'm trying to execute some binary with bash. I am getting a "Permission denied" message despite having given the full privileges (chmod 777) and being the 'root' user: This is the file description: -...
1
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2answers
2k views

newgrp and groups assigned via pam_group.so

For convenience reasons I tend to assign special group memberships like floppy, audio, plugdev, video etc. via /etc/security/group.conf (pam_group.so) mechanism instead of adding all users to this ...
0
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2answers
321 views

File permissions of file when tranferring from Windows to Unix

When I am uploading a file from windows PC to Unix ,the permissions of file are --wxr----t on unix machine , whereas umask is 0022 .I am not able to understand from where is the file getting ...
0
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2answers
92 views

'+' and 's' in permission strings

If the ls -l command gives me a permission string like rwsr-s--x What does the 's' mean? The only sources I found mention that it can be present sometimes but do not elaborate. What does a '+' ...
0
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0answers
378 views

DD-WRT: /tmp exec permission

After making a simple hello world OpenWrt package I installed it to the /tmp folder on the dd-wrt device. The program shows up in ls /tmp but when I try to execute it, it shows me /tmp/helloworld: ...
0
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1answer
909 views

Script with root permission [duplicate]

Possible Duplicate: Redirecting stdout to a file you don't have write permission on I am creating a script to change the brightness of my laptop. I discovered that I can do this using ...
42
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6answers
87k views

File permission issues with shared folders under Virtual Box (Ubuntu Guest, Windows Host)

I am using Ubuntu on Virtual Box and I have a folder which is shared between the host (Windows) and the VM (Ubuntu). When I open any file in the share folder in Ubuntu, I can not change it as its ...
22
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3answers
8k views

How to “jail” a process without being root?

Were I root, I could simply create a dummy user/group, set file permissions accordingly and execute the process as that user. However I am not, so is there any way to achieve this without being root?
43
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3answers
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What are common rights for /tmp ? I unintentionnally set it all public recursively

I have abused sudo. I have created a really really short life temporary directory that I wanted to share between some users for a few hours... and I named this directory /some/path/tmp Unfortunately ...
26
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2answers
7k views

How do I make a file NOT modifiable?

While logged in, I can do the following: mkdir foo touch foo/bar chmod 400 foo/bar chmod 500 foo Then I can open vim (not as root), edit bar, force a write with w!, and the file is modified. How ...
16
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7answers
13k views

What to use to backup files, preserving ACLs?

When using the tar utility to store files in backups one loses the extended ACLs. Is there some commonly used and not hackish solution (like: create a script that will recrate the ACLs from scratch) ...
9
votes
2answers
6k views

User can't touch -t

When SCP'ing to my Fedora server, a user keeps getting errors about not being able to modify file timestamps ("set time: operation not permitted"). The user is not the owner of the file, but we cannot ...
13
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4answers
72k views

Which is more widely used: chmod 777 or chmod a+rwx [closed]

Out of the two options to change permissions: chmod 777 file.txt chmod a+rwx file.txt I am writing a document to send out to our customers, detailing that they need to change the file permissions ...
10
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5answers
5k 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/ > ...
9
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2answers
9k views

USB drive permissions when automounting

On Debian there is the common problem, that you try to plug an ntfs formatted USB harddrive and then can't write to it as a regular user to it because the directory belongs to root. A little time ago ...
7
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5answers
2k 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 ...
6
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1answer
1k views

monitor file permission changes

How can I figure out which process is changing the permissions of a file? on a Debian server, I have the problem that something is changing the permissions on /dev/null every day at 6:20 (since 3 ...
4
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3answers
4k views

Why can't I run programs on another partition in Linux?

So for convenience, I store all my data on my Windows partition so that I can access my data easily from both Linux and Windows. However, I tried compiling a C++ program with g++, and found out that I ...
8
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3answers
4k 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 ...
8
votes
1answer
4k views

Difference between owner/root and RUID/EUID

I am relatively new to the concepts mentioned in the question and reading about them from different sources only makes them more confusing. So this is what I understood so far: When we are given ...
7
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2answers
9k 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 ...
4
votes
4answers
40k 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 (localhost:...
23
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1answer
43k 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 ...
19
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5answers
1k 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?
13
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7answers
84k 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
2answers
10k views

How to grant non-root user access to device files

I have device file that appears in /dev when a specific board is plugged in. The read and write operations to it work just fine, but in order to open the device file the program needs to be executed ...
7
votes
2answers
7k 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 ...
6
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2answers
24k views

Mount device with r/w access to specific user

How can I mount some device with read-write access to specific user?
6
votes
3answers
4k views

What is a process GID and what purpose does it serve?

Reading mod_wsgi's documentation I found you can choose which group to run the worker processes as. I can understand group ownership of files and how only a user who belongs to that group can achieve ...
5
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1answer
2k 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
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3answers
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How can I create a udev rule to mount a USB drive read only?

I'm trying to set a particular USB drive to always mount read only. If I plug it in, it is seen as sdb with a single partition, sdb1. Here are some relevant udevadm lines (not the entire output of ...
4
votes
2answers
2k views

Which user group can use the 'tap' net device?

I use the 'tap' net device with KVM to get my vm connect to the Internet. But I have to be root, or use 'sudo', which is inconvenient. I think I can put my user account into some group so I can access ...
3
votes
2answers
2k 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 (...
3
votes
2answers
8k 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 ...
3
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
32 views

Find differences of ownerships between two home folders?

I have two home folders: /home/masi and /home/masi_backup and I would like to find the differences between files of the two directories. Pseudocode vimdiff <`ls -la /home/masi` <`ls -la /home/...
12
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2answers
6k 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': ...
10
votes
4answers
3k views

set read and write permissions to folder and all its parent directories

I need to set read and write permissions for root user to directory subfolderN and all its parent folders till root. I can do it by hands: $ sudo chmod +rx /root/subfolder1/subfolder2/subfolderN $ ...
8
votes
3answers
11k 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 ...
8
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2answers
407 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 ...
8
votes
1answer
3k 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 ...
7
votes
1answer
4k views

Why cannot a user change group ownership of his own files? [duplicate]

Why cannot a user change the group permissions of files which he owns. Let's suppose I have user martin: $ ls -lAd /home/martin/ drwx------ 8 martin martin 4096 Apr 20 01:06 /home/martin/ For some ...
6
votes
2answers
32k 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, ...
5
votes
2answers
1k views

Which systems do not honor socket read/write permissions?

man 7 unix on Linux states: In the Linux implementation, sockets which are visible in the file system honor the permissions of the directory they are in. Their owner, group and their ...
5
votes
3answers
7k 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
9k 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, style....
4
votes
2answers
1k 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: zz@...
3
votes
3answers
240 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/ ...