Questions tagged [permissions]

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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18
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2answers
5k 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 ...
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2answers
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How to add a ssh user who only has permissions to access specific folder?

How to add an ssh user who only has permissions to access specific folder? useradd -d /var/www/xyz.com.tr/musteri -s /bin/bash -g sshd musteri I created a user called musteri. I set its home folder ...
18
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3answers
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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 ...
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2answers
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what is 'nogroup' group's purpose

When I list al groups I see one called 'nogroup'. What is this for? Is it supposed to be least privileged one or something? I'm using ubuntu 11.04.
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3answers
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What relationships tie ACL mask and standard group permission on a file?

At first I create a file and check it's standard permissions and ACL entries: $ touch file; ls -l file; getfacl file -rw-r--r-- 1 user user 0 Jul 30 16:26 file # file: file # owner: user # group: ...
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3answers
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How Do I check Permissions of Root Folder (/ Folder, not /root)?

Is there a way to check the permissions of the root folder, /? I mean the folder's permissions, not its content's (/var, /usr, etc.) permissions? Running ls /.. shows the content's permissions.
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5answers
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How does the OS know that a command needs sudo?

When you run an executable, sometimes the OS will deny your permission to. For example running make install with the prefix being a system path will need sudo, while with the prefix being a non-...
17
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3answers
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Purpose of permissions such as 0111 or 0333

What is the purpose of Linux permissions such as 111 or 333 (i.e. the user can execute, but cannot read the file), if the ability to execute does not automatically imply the ability to read?
17
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1answer
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ls -l vs ls -lL

I know this looks like a duplicate, but previously asked questions do not answer my question so in the shell I go to /home directory and create a directory there calling it play then I go to this ...
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4answers
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Permission denied to change gid(group) of a file I own

It appears I still miss some things about the way permissions work. I am on a debian 7 system btw. just now I have this file of which I downloaded and it belongs to myuser:myuser, that is both user ...
17
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4answers
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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. ...
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2answers
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What are the runtime 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?
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2answers
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Allow owner to create & read files, but not modify or delete

I would like to give a user permissions to create and read files in a particular directory, but not to modify or delete files. If the user can append to files that is ok, but I'd rather not. This is ...
17
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1answer
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Give default write permission to group to any newly created files and folders

Let's say that we have 2 users: a and b, that are both part of group general. I would like that any file or folder that A creates, would have write permission to the group GENERAL. How can I do it? ...
17
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1answer
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Executing a script in zsh - file permissions

I'm confused about execute file permissions not behaving as I expect. Probably because my expectations are wrong. Anyway: I have a script file, for simplicity is just called s, located in ~/bin. For ...
17
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2answers
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rsync: skip files for which I don't have permissions

I'm using rsync -rlptD to copy a directory from another user. There are a few files (I have no way of knowing these in advance) which I don't have permission to copy. Is there a way have rsync ignore ...
17
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1answer
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Tracing executable without read permissions

I found some surprising behavior on Ubuntu 14.04 when using strace on an executable, which I do not have read permission on. I wonder if this is a bug, or if some standard mandates this obscure ...
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2answers
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Why does “chmod 1777” and “chmod 3777” both set the sticky bit?

To set the sticky bit on a directory, why do the commands chmod 1777 and chmod 3777 both work?
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4answers
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Can I port user permissions across computers for an ext4 external hard drive?

I have an external USB 3 disk drive (2TB capacity) that is most likely going to be moved from machine to machine. The disk has a GUID partition table and an ext4 partition. I am unable to write to the ...
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2answers
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Getting “permission denied” when trying to append text onto a file using sudo [duplicate]

I'm using Amazon Linux. I'm trying to append some text onto a file. The file is owned by root. I thought by using "sudo", I could append the needed text, but I'm getting "permission denied", see ...
16
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3answers
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What is a capital X in posix / chmod?

I know what's ugoa (owner, group, others, all) or rwx (read/right/execute) or 4,2,1 or -, f, d, l, and I tried to read in man chmod to understand what's a capital X in chmod but there wasn't an entry ...
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5answers
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chmod recursive permission on thousands of files

This is a more general question about 'chmoding' recursively. I have this script which at some point needs to change the permissions recursively in a folder which has a few hundred thousand files. ...
16
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9answers
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Problem to launch java at Debian: “error while loading shared libraries: libjli.so”

I'm trying to launch java: $ java -version java: error while loading shared libraries: libjli.so: cannot open shared object file: No such file or directory $ ldd /usr/lib/jvm/java-6-openjdk/jre/bin/...
16
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1answer
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Group within group file permissions

I tried finding this on here, but couldn't so sorry if it's a duplicate. Say I have 2 groups and a user: group1, group2, user1 with the following structure: group1 is a member of group 2, user1 is a ...
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5answers
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Why are files in a smbfs mounted share created with executable bit set?

I mounted a samba share using the smbmount command: $ sudo smbmount \\\\foo\\bar /mnt/bar -o user=tom When I create new files, they get created with the executable bit set for owner, group and ...
15
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3answers
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What does GID mean?

What does GID actually mean? I have Googled it and this is what linux.about.com said: Group identification number for the process. Valid group numbers are given in /etc/group, and in the GID field ...
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4answers
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What are the world writable directories by default?

In a standard Linux filesystem, which of these common directories are world-writable by default? /tmp /etc /var /proc /bin /boot /.... .... Why are they world-writable? Does that pose a ...
15
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2answers
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How to Change Owner of a Directory

EDIT: The problem was that Apple uses permissions to mark backups and prevents you from modifying them (probably a security feature). By using chmod -RN <dir> I removed ACL data from all the ...
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7answers
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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:...
15
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6answers
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Downsides of umask 077?

What are the cons, for having a restrictive umask of 077? A lot of distros (I believe all, except Red Hat? ) have a default umask of 022, configured in /etc/profile. This seems way too insecure for a ...
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4answers
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Is there a tool to find out the general state of the machine? [closed]

I am longing for a tool for linux that would give me a general idea what is happening on a machine. Example information I am looking for: What daemons are installed (www, db, others) Config locations ...
15
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1answer
445 views

Why does ArchLinux keep some users/groups after package uninstallation?

I've noticed that after uninstalling the postgresql package in ArchLinux the postgres user and group are not removed automatically. The same is true for some other packages. Investigating this further,...
15
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2answers
87k views

Give read-only access to specific folders?

I would like to give read-only access to a user but I want him/her to see only the exact folders I give access. for example he/she shouldn't travel around all the server and browse to all users ...
15
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4answers
17k 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 ...
15
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1answer
3k views

Can I restrict a user to use special programs?

Is it possible to add a user and restrict him to run special programs? For example after this user logs in, he can only open Firefox to use Internet and no other programs can be run by this user. For ...
14
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3answers
3k views

Is there a file that always exists and a 'normal' user can't lstat it?

I need this for a unit test. There's a function that does lstat on the file path passed as its parameter. I have to trigger the code path where the lstat fails (because the code coverage has to reach ...
14
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3answers
8k views

Who can change the permissions of a file/directory?

I believe (not sure) that the owner of a file/directory and the root user are the only users that are allowed to change the permissions of a file/directory. Am I correct or are there other users that ...
14
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2answers
5k views

chown removes setuid bit: bug or feature?

Steps to reproduce: germar@host:~$ cd /tmp/ germar@host:/tmp$ touch test && chmod u+s test && ls -la test -rwSr--r-- 1 germar germar 0 Nov 2 20:11 test germar@host:/tmp$ chown germar:...
14
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2answers
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List all flags of a file?

Is there a way to see a file's flags, such as hidden, schg, etc? I've got an rwxrwxrwx file that I can't edit, and I think a flag might be responsible.
14
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3answers
103k views

Giving PHP permission to write to files and folders

UPDATED FOR FURTHER CLARITY: According to http://expressionengine.com/user_guide/installation/installation.html, it says: For most Unix hosts the following is typical, but you may check with your ...
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2answers
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Why can't root on one machine change nfs mounted content from another machine?

On my NFS server, I have the following export defined: #NFS exports Database /shared -alldirs -network=192.168.1 -mask=255.255.255.0 On my NFS client: 192.168.1.7:/shared /shared nfs rw 0 0 ...
14
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1answer
1k views

How is file owner and group remembered for an external drive?

I formatted an external hard drive with an ext4 partition and subsequently mounted it. So that I could use the new partition, I did: sudo chown me:me /mount/directory to change the file owner and ...
14
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3answers
58k views

How to check which Apache group I can use for the web server to write?

I'm trying to make Wordpress work. I currently have this error message: Could not create directory. /var/www/html/wp-content/upgrade/theme_name when trying to upload a theme. This is the permissions ...
14
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1answer
32k 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 ...
14
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1answer
43k views

How are file permissions applied to newly created files?

I have a directory that has the following permissions set: drwxr-s---. user group folder On the desktop, I access this folder and right click to create a new file call foo.txt. Then using the ...
14
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2answers
21k views

What is a regular file?

$ rm foobar rm: remove regular file `foobar'? What does it mean for a file to be "regular" and why does rm treat such a file as a special case?
14
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3answers
22k views

How to make a folder private?

I'm using Ubuntu with several users and I want to make folders viewable just for a specific user. Any idea how to do it?
14
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1answer
26k views

Cannot delete a file - permission denied - why?

[db2inst1][testing ~/sqllib/db2dump] rm db2diag.log rm: cannot remove `db2diag.log': Permission denied [db2inst1][testing ~/sqllib/db2dump] id uid=1002(db2inst1) gid=107(db2iadm1) groups=16(dialout),...
14
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2answers
4k views

Why can't I list a directory with read permissions?

I created a directory d and a file f inside it. I then gave myself only read permissions on that directory. I understand this should mean I can list the files (e.g. here), but I can't. will@wrmpb /p/...
14
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3answers
6k views

How do I let an SDL app (not running as root) use the console

I want to use an SDL-based program to display graphics on the console, without having to log on from the console, and without running the program as root. For example, I want to be able to run it via ...

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