Short for "file system permissions" - access control based on user, group, or global access.

learn more… | top users | synonyms (2)

206
votes
5answers
1.1m views

Change folder permissions and ownership

I would like the user to have full rights on this folder (as well as all sub-directories and files in it): ~/.blabla currently owned by root. I have found numerous posts (in this forum and ...
172
votes
5answers
144k views

How can I get octal file permissions from command line?

There is a chmod command to set file permissions, but can I get file permissions in octal mode (such as 755) from the command line?
132
votes
7answers
218k views

How do I change my username?

Some time ago when I installed Ubuntu I chose a rather stupid username for my account that I do not want to use anymore. How do I change this (including the name of my home directory, and the name ...
101
votes
7answers
187k views

Whats the simplest way to edit and add files to “/var/www”?

Having installed the web server is there a simple way to set a user able to use the graphic interface to copy files and directories to the local web server /var/www I gave myself administrative ...
90
votes
9answers
112k views

How do I use 'chmod' on an NTFS (or FAT32) partition?

I have a script that I need to execute on an NTFS partition. The script's permission is set to 600. I attempted to modify the permissions by running chmod 755 script.sh, which doesn't report a ...
86
votes
4answers
143k views

What is “umask” and how does it work?

I believe that umask is something that controls file permissions, but do not fully understand it. After running umask 0644 in a terminal, I cannot read the files I create with the command-line text ...
67
votes
4answers
58k views

Why doesn't `sudo cd /var/named` work?

I want to cd into /var/named but it gives me a permission denied error, and when I want to use sudo to do this I am not permitted. What is the technical reason for this, and is it possible to do this ...
65
votes
4answers
74k views

How do I run wireshark, with root-privileges?

A standard installation of Wireshark doesn't give the program permission to access the network interface. I suppose I have to run the program with sudo, but do not know how to add it to the icon - ...
56
votes
3answers
29k views

What is the difference between the 'sudo' and 'admin' group?

I noticed that two groups are granted similar-looking permissions in /etc/sudoers: # Members of the admin group may gain root privileges %admin ALL=(ALL) ALL # Allow members of group sudo to execute ...
53
votes
3answers
68k views

What is the “t” letter in the output of “ls -ld /tmp”?

When running the command ls -ld /tmp, the output would be: drwxrwxrwt 30 root root 20480 Mar 11 14:17 /tmp So I have two main questions: What is the letter t after the permissions? As far as I ...
52
votes
3answers
185k views

'chmod u+x' versus 'chmod +x'

What is the difference between chmod u+x and just chmod +x? I have seen a ton of tutorials that say to use u+x to make scripts executable. However, the u is not mentioned in the chmod help or manual....
51
votes
2answers
29k views

Why shouldn't /var/www have chmod 777

When developing a page on a localhost, I sometimes get a "Permission denied" error which I can solve by running chmod -R 777 /var/www. However, people are telling me that this is a bad idea for ...
49
votes
7answers
10k views

Why is 777 assigned to chmod to permit everything on a file?

I was asked in an interview why it is that 777 is assigned to take all permissions for a file. Why not 555? He said that there is reason for everything. So, what is the reason for 777? Why not any ...
43
votes
6answers
33k views

Npm errors when installing packages on windows share

I have Ubuntu 12.10 running as a VMware guest on my Windows 8 host. I have shared a folder on my Windows 8 Host and it is mounted in the Ubuntu guest on startup using this entry in fstab: //myhost/...
41
votes
5answers
133k views

How can I recursively change the permissions of files and directories?

I have ubuntu installed on my local computer with apache / php / mysql. I now have a directory at /var/www - inside which I have several of my ongoing projects. I also work with opensource ( drupal, ...
40
votes
3answers
34k views

How do I add myself back as a sudo user?

I clean-installed Ubuntu 11.10 today, and then installed VirtualBox. This required me to add myself to the vboxusers group, and since 11.10 seems to no longer have a graphical app to add users to a ...
35
votes
4answers
150k views

How to find owner and group of a directory?

How can I find out owner and group of a directory in Ubuntu?
32
votes
9answers
141k views

How do I get permissions to edit system configuration files?

I can't seem to edit and save config files in the root system (eg: /etc/dhcp/dhcpd.config); it just says "permission denied" or the save option is blocked in the text editor. I'm pretty sure I'm a ...
31
votes
6answers
185k views

How do I correctly mount a NTFS partition in /etc/fstab?

After a nasty episode (my second, you'd think I'd learn) caused by unsupervised automated podcast downloads filling my entire partition, I've finally moved just ~/Music to its own partition. The ...
28
votes
3answers
265k views

ERROR 1045(28000) : Access denied for user 'root@localhost' (using password: no )

I'm trying to install queXS cati app on my Ubuntu desktop and I installed MySQL server and PHP 5 and I cannot login into MySQL server as root without password: mysql -u root it says ERROR 1045(...
26
votes
6answers
13k views

What if I accidentally run command “chmod -R” on system directories (/, /etc, …)

I accidently ran sudo chmod 755 -R / instead of sudo chmod 755 -R ./ I stopped it after few seconds, but now there is some problems such as sudo: must be setuid root How can I revert ...
25
votes
2answers
126k views

give specific user permission to write to a folder using +w notation

I know I can assign the permission to write to an owner\group\others like this: chmod u+w myfolder Can I specify the specific user here? Some like this: chmod username u+w myfolder
24
votes
4answers
96k views

Permissions issue: how can Apache access files in my Home directory?

I know file permissions have been covered on here before, but im struggling to get my head around the concept for my scenario. I created the files on an old ubuntu installation. Ive copied the ...
24
votes
3answers
77k views

How to show current permissions of a folder

I want to find out who has what permissions on a certain folder. How would I go about viewing this? The folder in question is /srv/www
23
votes
4answers
61k views

Change owner of internal hard drive partition from root to user

I have a number of drives internal and external. Some are partitioned. Most mount automatically at boot (all did at one point). One partition is owned by root and therefore does not mount ...
22
votes
5answers
45k views

How to make Apache run as current user

I think for a development machine, its more convenient to run Apache as the current user to simplify permissions problem? How do I do that? I think its suexec but how do I configure it in Ubuntu+...
22
votes
6answers
4k views

Under what license is Ubuntu? Can it be legally modified and distributed?

What license does Ubuntu fall into (GPL, MIT, a mix)? Would it be legal to modify it and redistribute my modified version?
22
votes
3answers
65k views

Read Only usb stick that won't let me do anything to it

Somehow I messed up and accidentally made my usb stick into a read only file system. I have tried a bunch of things to delete the files, including the basic (rm -f myfile) and attempting to allow ...
21
votes
6answers
1k views

How to make super-user permissions last longer than using sudo? [duplicate]

Is there a way through which I can make the sudo command give me permissions for a longer period than its default time? It can be a pain having to keep entering the sudo password, when requiring the ...
21
votes
4answers
53k views

Apache: access denied because search permissions are missing

I know this question is asked a lot, but the solutions I saw didn't work for me. I only have one virtual host enabled, and I'm trying to enable access to a folder that's not under the document roots ...
21
votes
2answers
9k views

How do file permissions work?

Can you explain briefly the main concepts and command line tools used to manage file permissions?
20
votes
8answers
154k views

SSH Permission denied (publickey)

I have tried searching previous questions for answers to my question but all of the answers that have been suggested previously haven't worked for me. I am trying to connect to a linode (running ...
20
votes
1answer
2k views

How do I prevent one user in particular from accessing my home directory?

There's a specific user that I don't want to be able to access my home directory. How do I deny access to them, while still allowing access to others who would normally have it?
20
votes
2answers
27k views

Adding user to a group - Why had to reboot?

I was not able to access the VirtualBox shared folder, so I made the user part of the vboxsf group. But, still not able to access it. Rebooting the guest resolved the problem. Is it a bug? A reboot is ...
19
votes
5answers
73k views

Changing permissions on serial port

I'm using the Arduino IDE in Ubuntu, and am having issues with the serial port. It has worked in the past, but for reasons that may be unnecesary, I felt the need to change the ownership of some of ...
19
votes
5answers
18k views

Why can other users see the files in my home folder?

I just added a new, underprivileged "desktop user," and I was surprised to discover that it can see the files in my home folder. What is the rational for setting up such lax permissions?
19
votes
2answers
44k views

How do I give www-data user to a folder in my home folder?

I have a folder: /home/myuser/folderA I want to give www-data user write access to the above, while 'myuser' continues to have normal access (as it is myuser's home folder anyway). Which commands do ...
19
votes
5answers
89k views

How can I change permissions on external drives?

I wanted to change permissions on my external drives that are automounted however I have tried by sudo nautilus and then going to gui and permissions and changing it however it does not let me. I ran ...
19
votes
1answer
1k views

How Will App Permissions be Handled in Ubuntu Touch?

Most elements of the hardware, or data sets shared between apps on the Android and iOS platform are controlled strongly, and only provided to apps explicitly on a need-to-know basis. This can allow ...
18
votes
2answers
2k views

Is it a bad idea to run SELinux and AppArmor at the same time?

My corporate policy says that Linux boxes must be secured with SELinux (so that a security auditor can check the 'yes, we're extremely secure!' checkbox for each server). I had hoped to take ...
18
votes
5answers
67k views

How do I edit the /etc/hosts file?

I'm new at Linux and I just download Ubuntu 12.04 LTS. I found a spot that showed me how join my Windows Active Directory. It has me add couple lines into the 'hosts' but I'm not able to edit the ...
18
votes
1answer
54k views

Correct way of mounting a Windows share

I mounted a Windows share to my Ubuntu 11.10 system via adding the following line to the /etc/fstab: //serveraddr/sharedfolder /mnt/foldername/ smbfs credentials=/home/myname/.smbpasswd 0 0 using ...
17
votes
3answers
606 views

When are “User Privileges” relevant?

I notice that many of the user privileges in "Users and Groups" are not ticked on my user, but I still have access to the items they specify. For example, I'm constantly using VirtualBox for ...
16
votes
9answers
23k views

How to run an Application as another user?

I use krusader for file management stuff. the problem is that apache's DocumentRoot should be under chown www-data:www-data /path/to/www. so using krusader (which is run under my account) I've not ...
16
votes
6answers
29k views

“Welcome to emergency mode!” Think it is a fsck problem

journalctl -xb snippet (what i think is wrong, it was at least in red): -- Unit systemd-fsckd.service has begun starting up. juli 09 15:40:16 kim-SSD-Sationary systemd-fsck[414]: /dev/sdb1 contains a ...
16
votes
1answer
47k views

How can i check the folder permissions in ubuntu server 12.04?

Right now, I know that I can change persmissions for example with : sudo chmod 550 directory I wonder how I can check the actual folder permission.
16
votes
1answer
92k views

How can I set up Samba shares to only be accessed by certain users?

I have a RAID10 array mounted on Ubuntu Server 12.04. I have created a few folders within the mount point and want the following functionality. There will be 4 users, 3 of them are windows users: '...
16
votes
7answers
25k views

What is the correct way to share directories in Mac and Ubuntu with correct permissions?

In VirtualBox, what is the best way to share a directory between an OS X host and Ubuntu guest? Host: Mac OS X 10.7.3 Guest: Ubuntu 12.04 Guest has a shared directory mounted via VirtualBox settings ...
16
votes
2answers
16k views

What's an upper 'T' at the end of unix permissions?

What's that 'T' in the permissions mean, and how does it work? Is it related to this 'sticky bit' thing I've heard about but never quite understood?
15
votes
4answers
3k views