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

learn more… | top users | synonyms (2)

162
votes
5answers
829k 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 ...
139
votes
5answers
115k 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?
114
votes
7answers
171k 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 ...
90
votes
7answers
160k 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 ...
82
votes
9answers
96k 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 ...
77
votes
2answers
111k 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 ...
57
votes
4answers
60k 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 - ...
54
votes
3answers
25k 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 ...
50
votes
4answers
39k 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 ...
48
votes
7answers
9k 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 ...
47
votes
3answers
55k 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 ...
46
votes
3answers
26k 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 ...
44
votes
3answers
155k 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 ...
37
votes
6answers
28k 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: ...
37
votes
5answers
109k 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, ...
34
votes
3answers
28k 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 ...
30
votes
9answers
117k 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 ...
28
votes
4answers
107k views

How to find owner and group of a directory?

How can I find out owner and group of a directory in Ubuntu?
26
votes
6answers
162k 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 ...
22
votes
3answers
64k 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
22
votes
3answers
212k views

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

I got a problem with mysql server Actually i am not sure im tring to install queXS cati app on my ubuntu desktop i installed mysql server and php5 and when im trying mysql -u root it says ...
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
2answers
8k views

How do file permissions work?

Can you explain briefly the main concepts and command line tools used to manage file permissions?
20
votes
6answers
3k 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?
20
votes
4answers
79k 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 ...
20
votes
4answers
52k 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 ...
20
votes
1answer
1k 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?
18
votes
4answers
10k 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 ...
18
votes
5answers
16k 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?
18
votes
1answer
49k 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 ...
18
votes
3answers
56k 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 ...
18
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 ...
17
votes
4answers
55k 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 ...
17
votes
5answers
37k 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 ...
17
votes
4answers
76k 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 ...
17
votes
2answers
22k 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 ...
17
votes
3answers
603 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
22k 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
2answers
12k 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
2k views
15
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 ...
15
votes
2answers
624 views

Default owners/permissions of files in user home directory

I often see users that try to fix an issue and somewhere read or just try to recursively chown their home directory and sometimes even also reset permissions recursively to something like rwxr-xr-x or ...
15
votes
1answer
75k 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: ...
15
votes
4answers
36k views

Mount NTFS partition at startup, with non-root user as owner

I'm currently mounting an NTFS partition at startup using the following line in /etc/fstab: /dev/sda3 /media/data ntfs nls=iso8859-1,umask=000 To my Ubuntu 11.10 installation, ...
15
votes
4answers
13k views

iOS 7 Locked Bug via Ubuntu 13.10

I wanted to bring up an issue with the latest Ubuntu release that I hope can be solved. Although I will agree with the community that iOS 7 is not the most open platform release, it still is my desire ...
14
votes
3answers
15k views

How to mark “allow executing file as program” on an external drive

If I try to set this option for a file on an external drive it just unmarks itself. Doing chmod +x has no effect. The drive is mounted with default options.
14
votes
7answers
110k 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 ...
14
votes
2answers
546 views

Change owner of files recursively, but not directories

I have a directory that has ~50k directories and ~1m files. I want to change owner (or permission) of all files, but not the directories. This is because i'm trying to SCP additional files from a ...
14
votes
1answer
1k views

How is my internet browser able to write files into my “Downloads” file if the default permissions do not allow to “write”?

On the terminal, I used this command: stat Downloads It stated the permissions for my downloads folder were "drwxr-xr-x" Wouldn't this mean only the admin and owner would be able to edit the ...
14
votes
2answers
35k 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 ...