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

learn more… | top users | synonyms (2)

66
votes
9answers
6k views

Run same command again but as sudo

Sometimes when I run a command I don't notice that I needed to run it as super user to have enough permission. Is there a way to run the same command again but as a super user?
60
votes
4answers
63k views

How do I sudo a command in a script without being asked for a password?

I want to turn my system on automatically every day. So I use the below code in my Python script, but sudo asks me for a password every time: os.system('sudo sh -c "echo date \'+%s\' -d \'+ \ ...
55
votes
5answers
92k views

How do I add a user to the “sudo” group?

In /etc/sudoers I see this: # Allow members of group sudo to execute any command after they have # provided their password # (Note that later entries override this, so you might need to move # it ...
54
votes
6answers
236k 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 ...
53
votes
7answers
75k 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 ...
49
votes
4answers
40k 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) without ...
48
votes
8answers
37k 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 ...
38
votes
4answers
12k 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 ...
36
votes
3answers
28k 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?
35
votes
2answers
14k 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 ...
31
votes
2answers
26k 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 ...
24
votes
4answers
5k views

When using sudo with redirection, I get 'permission denied'

When using sudo to allow edits to files, I regularly get 'permission denied'. For example, my mouse is jittery and sluggish, so I want to disable polling: sudo echo "options drm_kms_helper ...
22
votes
7answers
50k 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 ...
22
votes
3answers
2k views

What is the “sticky bit” (t permission) and why does /tmp have it?

The command ls -ld /tmp gives drwxrwxrwt 30 root root 20480 Mar 11 14:17 /tmp What is the letter t after the permissions? As far as I know /tmp is used to create temporary files related to ...
19
votes
3answers
61k 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 ...
18
votes
3answers
11k 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 ...
18
votes
3answers
151k views

How do I install .run files?

My PC has both Ubuntu and Windows 7 installed. I have installed all my drivers in Windows like NVidia graphics, motherboard etc. Shall I install them in Ubuntu too? I looked on the web for my Nvidia ...
17
votes
7answers
1k 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?
17
votes
3answers
568 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
4answers
35k 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, ...
15
votes
3answers
3k views

How do file permissions work?

Can you explain briefly the main concepts and command line tools used to manage file permissions?
14
votes
3answers
5k 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 ...
14
votes
3answers
11k 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 ...
14
votes
8answers
14k 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 ...
14
votes
1answer
570 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 ...
13
votes
4answers
22k 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 ...
13
votes
5answers
8k 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?
13
votes
4answers
574 views

Good and easy way to share files on local machine

I would like to have a directory that has following properties: Many users can copy files into it These files can be deleted/changed by these users (user A can delete/modify file that was copied ...
12
votes
4answers
893 views
12
votes
2answers
1k views

How can I rename items in places I don't own, like / , and why shouldn't I?

I get a Permission denied message when trying to rename files and folders in places like /, /usr, and other people's home directories. I'm an administrator. How can I do this? Also, I've heard that ...
12
votes
1answer
25k 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 ...
12
votes
4answers
29k 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 ...
12
votes
1answer
292 views

How to take ownership over an existing Ubuntu Software Center app?

My name is Michael Tunnell and I am one of the project members of the download manager, uGet. uGet has been out of date in Ubuntu for over a YEAR and we are trying to fix that. (You can verify my ...
12
votes
2answers
4k views

What do the groups do in “Users and Groups”?

I know that some define permissions on the file system (such as www-data). But I don't understand why this question was answered successfully by adding a user to the "Video" group. So the question ...
11
votes
3answers
74k 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 ...
11
votes
4answers
6k views

.exe file permission fail

I'm trying to run a exe file that is located on my Vista partition, when I browse to the file and try to change the file to run as executable the tick box unticks itself right after i tick it, i tried ...
11
votes
2answers
1k 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 ...
11
votes
7answers
2k views

Mounting a Windows folder with writing permissions in Ubuntu

Apparently the answer is here: http://superuser.com/questions/251537/mount-specific-ntfs-directory-on-linux however it is not working as expected. I have a dual boot system with Windows 7 and Ubuntu ...
11
votes
3answers
13k views

Can't set permissions for files on an NTFS partition

I remember that I was able to run a Linux .exe that was placed on an NTFS partition earlier before I installed 10.10 RC. But if I try to run it now, I can't run it as it hasn't the execution ...
11
votes
3answers
32k 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 ...
11
votes
4answers
2k views

Hide 'Your profile could not be opened correctly'

I have a small public internet cafe, with Ubuntu 10.04 and 10.10. I'm using Google Chrome 7.0.517.44 (64615), with AutoScroll - Version: 2.7.5; AdBlock is removed because of high CPU loads, and ...
10
votes
4answers
3k views

What if I accidently 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 ...
10
votes
3answers
8k 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.
10
votes
2answers
16k views

Minecraft jar not marked as executable

I looked up several tutorials on how to install and they dont work. I do everything correctly but then i get this: The file '/home/mike/Downloads/minecraft.jar' is not marked as executable. ...
10
votes
3answers
14k 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 ...
10
votes
5answers
14k views

Apache symlinked to home directory - Permission Errors

im having a few problems symlinking my /var/www/ to a new Webroot directory inside my home folder. I think these stem from my lack of understanding of linux permissions. As far as im aware, symlinks ...
10
votes
4answers
6k views

How can I run an executable from a CD when it doesn't have the executable bit set?

A textbook I'm using came with a CD containing a few supplementary applications. To my pleasant surprise, it appears to include an installer for Linux. The readme file on the CD provides the ...
10
votes
1answer
552 views

Why use sticky bit?

"The sticky bit applies only to directories, and is typically used on publicly-writeable directories. Within a directory upon which the sticky bit is applied, users are prevented from deleting or ...
10
votes
1answer
7k views

What user settings control audio access?

Running a regularly updated 10.04 LTS we have a weird issue with access to audio with pulseaudio 0.9.22. Sound device is ATI Technologies Inc SBx00 Azalia (Intel HDA) Login user1 after reboot: sound ...
10
votes
2answers
276 views

How can I preserve the executable bit on a file that is synchronized by Ubuntu One?

A script I am working on is in a folder that is synchronized by Ubuntu One. Every time I edit it from another computer, it looses its executable bit and I must manually reapply chmod +x. How can I ...