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.

learn more… | top users | synonyms (1)

7
votes
5answers
284 views

Changing Unix group for files

I have a file that a colleague and I are editing together, on a Unix system. We are using Unix group permissions to edit it. We have one Unix group that we are both members of. Whenever I save the ...
6
votes
7answers
371 views

File protection in Unix

Is there a way to protect a file in such a way that even root cannot delete it or rewrite it after creating it? I have a file which is created by root under /var/log/ and I want to restrict all users ...
6
votes
5answers
3k views

How to setup password-less ssh with RSA keys

I am trying to setup a password-less SSH configuration between two machines and I am having a problem. There are a ton of howtos out there that I have followed and have had no success. Here are the ...
6
votes
2answers
20k views

Unable to delete file, even as root

I've got a file on remote machine (saying that, cause I don't know who the heck created it), that I've to remove. user@machine:~/folder$ ls lift_proto.db.lock.db And permissions are like this: ...
5
votes
2answers
146 views

Why do Linux/POSIX have lchown but no lchmod?

It seems that Linux supports changing the owner of a symbolic link (i.e. lchown) but changing the mode/permission of a symbolic link (i.e. lchmod) is not supported. As far as I can see this is in ...
5
votes
2answers
18k views

What are the 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?
5
votes
2answers
2k views

How can I ensure only the root user have the right to halt/reboot the system?

CentOS Linux by default allows all users to have permission to "halt" & "reboot" the system by using the commands halt and reboot. How can I configure my system so that only the root user has the ...
5
votes
2answers
2k views

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. ...
5
votes
2answers
483 views

Is it possible to represent the +X symbolic permission with an octal value?

Is it possible to represent the +X symbolic permission with an octal value? The chmod(1) man page says: execute/search only if the file is a directory or already has execute permission for some ...
5
votes
3answers
2k views

Frustrating issue where neither cron nor su -c runs my job (permissions?)

Updated (and snipped) with more details below. I've set up a cron script and I'm trying to debug why it's not running. [Snipped context testing, which is all ok; see revision 2 for details] The ...
5
votes
1answer
6k views

mv file without write permission to the source file

I just realised that I can move a file that I do not own and don't have write permissions on. I have write permissions to the directory, so I am guessing that is why I could move it, but in this ...
4
votes
1answer
646 views

Why are execute permissions required to rename files in a directory?

Say I'm the owner of a directory and I have read and write permissions, but not execute permissions, where the directory structure is like this: x/ (drw-r--r--) y (-rw-r--r--) ...
4
votes
1answer
2k 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 ...
4
votes
2answers
945 views

How can I backup a directory to NTFS while preserving Unix file attributes?

I want to make a backup of my home directory to an NTFS partition (an unfortunate limitation). However, when I last tried using just cp, the attributes (owner, etc) went away. How can I make a backup ...
4
votes
6answers
46k views

Transfer files using scp: permission denied

I try to transfer files from remote computer using ssh to my computer : scp My_file.txt user_id@server:/Home This should put My_file.txt in the home folder on my own computer, right? I get ...
4
votes
1answer
2k views

How to configure permissions to allow apache to securely have access to a file in a shared environment?

This is a follow up question from my previous, but I felt it might be more Linux based. http://serverfault.com/questions/414207/how-to-set-linux-permissions-to-allow-apache-to-have-access-to-a-file ...
3
votes
1answer
2k views

Help with giving group permissions to other user's files

I'm a linux beginner using Debian 7 and have created a new user (a website) with an htdocs directory like this: $ sudo adduser website $ sudo mkdir -p /home/website/htdocs $ sudo chown -R website ...
3
votes
1answer
8k views

File inheriting permission of directory it is copied in?

I have files created into my home directory with only user read permission (r-- --- ---). I want to copy this file to another directory /etc/test/ which has the folder permission of 744 (rwx r-- r--). ...
3
votes
1answer
3k views

permission denied for ptrace under GDB

I initially posted this question on StackOverflow, as a GDB problem. I didn't find a solution there, but they did help me find that it's a permissions problem, so I'm posting it here. I have set a ...
3
votes
1answer
3k views

Running executables on an NTFS partition?

My system configuration is the following: UEFI computer Dual-boot with Windows 8 and Linux Mint 15 Olivia I would like to be able to run Linux executables that are stored on an NTFS partition ...
3
votes
2answers
282 views

File permissions and saving

Let's say you open a file on which you have write permission. Meanwhile you change permissions and remove write permission while you still have the file open in some editor. What will happen if you ...
3
votes
2answers
998 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 ...
3
votes
4answers
11k views

What type of permissions should a user's home directory and files have?

I'm working with a fresh install of Ubuntu 12.04 and I've just added a new user: useradd -m testuser I thought that the -m flag to create a home directory for users was pretty standard, but now ...
3
votes
2answers
434 views

Running user script with root permissions

I have a script that I've made that needs to have root permissions to enable and disable bluetooth features. I am binding this to a button so it is not feasible to log in as root to run the script. ...
3
votes
2answers
3k views

Taking file ownership when file and directory is readable/writable

I got some files in directory: drwxrws-wt 2 me mygroup 4,0K 10.1. 12:34 . -rw-r----- 1 someone mygroup 10G 10.1. 11:22 someonesfile me and someone are regular users without supplementary ...
3
votes
1answer
579 views

What does it mean if a directory has only x (executable) permission for certain user/group?

I stumbled across the directory /etc/ssl/private on Ubuntu (12.04), it has following permission: drwx--x--- 2 root ssl-cert 4096 7月 8 2012 private/ I wonder what does this mean for group ...
3
votes
2answers
1k views

A question about permissions of hierarchical directories

I have some directories, with following permissions: drwxr-xr-x 18 user1 root 4096 Oct 27 11:25 /home/test1/test2 drwxr-xr-x 24 user1 root 4096 Oct 21 08:38 /home/test1 drwxr-xr-x 492 root root 12288 ...
3
votes
3answers
388 views

Setting execution right to whole directory - is it good or bad idea?

I have a zip file containing lot of files and directories for a certain application which should be running on Linux. Some files needs to be set as executable, but the zip file format afaik does not ...
3
votes
2answers
5k views

how to chown mounted device?

When I plug in my external hard-drive when running KDE, it prompts me to mount the device (by clicking an icon, no sudo involved), and once I've done that I am the owner of the files. This is great. ...
3
votes
2answers
1k views

What directories/file permissions should i ensure are set?

I have a similar question about default software configuration. For this question i would like to ask What directories/file permissions should i ensure are set? Aprrently Is it normal to get ...
3
votes
4answers
299 views

Backup script permission issue

I have a server with a user named deploy-user and have written a backup script to backup a number of websites associated with this user. However one of the sites I'm trying to backup has a directory ...
2
votes
2answers
546 views

warning: Filesystem seems to be mounted read-only

I have an old SGI indigo with an EFS file system (Extent File System ), and the password needs to be reset. I can mount the hard drive, but read-only. I need write permissions. # mount --rw -t efs ...
2
votes
1answer
247 views

Allow certain guests to execute certain commands

I would like to create a new user on some of my Debian/Ubuntu hosts that is able to update the server using the commands apt-get update and apt-get dist-upgrade, but I do not wan't to give them full ...
2
votes
2answers
111 views

How does one permissibly access files on non-booted system's user's home folder?

I have a dual boot system with Mint 17.1 and Centos 6.6 I want to access a file in my CentOS user's home directory from Mint. (I cannot boot CentOS right now.) What is a clean/standard method for ...
2
votes
3answers
91 views

setting default permission for directory

Before anyone tags this question as duplicate, I would like to emphasize that I would like to know something extra... I found a way to set the default file permissions for all files created in a ...
2
votes
4answers
14k views

'chmod g+s' command

Hello I want to understand the role of the chmod g+s command in Unix. I also would like to know what it does in this particular context: cd /home/canard; touch un; chgrp canard .; chmod g+s .; touch ...
2
votes
1answer
109 views

Do root's supplementary groups behave differently than regular account ones for NFS shares?

OS: Linux CentOS 7, NFSv4 On one machine I exported an NFS share group-owned by the nfsgroup with 2770 privileges for group collaboration: groupadd -g 5000 nfsgroup chown nobody:nfsgroup ...
2
votes
1answer
230 views

How do I mount a Windows folder on Linux (with Samba) and see the correct permissions?

I have a Windows 7 box and a Linux machine. I can correctly access the files on the Windows machine from the Linux machine. however, when I look at the permissions from Linux and from Cygwin on my ...
2
votes
1answer
269 views

In a Virtualbox VM how do I set the filesystem permissions?

I have a virtualbox VM with arch Linux running on my windows PC (which I unfortunately have to use for work). I use this to work on my windows PC with a Linux environment as an alternative to Cygwin. ...
2
votes
1answer
926 views

/usr/sbin/sendmail: Permission denied

I am trying to setup the mail on my fedora 20. Every time I try to fire a test mail it tells me the permission is denied on /usr/sbin/sendmail. I checked the permissions and this is the output: ...
2
votes
1answer
388 views

How to add a read only group permission to a folder that already has a default group, and have it inherited for all newly created files & folders?

In Windows this is easy. I never fully figured out Linux permissions, I have a directory such as this: /Photos The current ACL permissions are as follows: owner: root - full access group: photos ...
2
votes
1answer
239 views

chmod 600 fails silently

Here is what happens: $ chmod 600 foobar.txt $ ls -l total 1 -rwx------ 0 sampablokuper sampablokuper 13 Feb 19 21:00 foobar.txt Why is the last line not reading as follows? -rw------- 0 ...
2
votes
1answer
1k views

How do I grant someone else access to my linux server

If you administer a Linux server, what steps do you take to properly grant someone else access? Assuming they will log in over ssh, don't already have an account, and will need root access. ...
2
votes
1answer
206 views

Adding a user to a group by default

I have a group that all users on the system share. The group name is common and it is to allow for a universal fileshare for everyone on the machine. How would I make it so that all new users are ...
2
votes
5answers
2k views

How do I disable copy permissions?

Can we set permissions, on a Linux box OR for a particular directory (Scientific Linux in my case) that, one can read files but cannot copy, move or delete them? Update: My Scenario is, We developed ...
2
votes
1answer
2k views

Why can't I use strace with rsh?

If I run rsh, it works, but prints some strange “Connection refused” messages at the beginning: $ rsh localhost pwd connect to address 127.0.0.1 port 544: Connection refused Trying krb4 rsh... ...
2
votes
1answer
1k views

How to suid iwconfig on Debian wheezy?

I have a script running under my own user account that takes care of all sorts of wireless interfaces. It (more or less) intelligently switches wireless LAN off and on and so forth. However, it does ...
2
votes
3answers
744 views

How does gcc handle file permissions?

The executable files that gcc creates have execution permissions -rwxrwxr-x which are different than the permissions that the source file has. -rw-rw-r-- How does gcc set these permissions ?
2
votes
2answers
696 views

Gaining root privileges in SCO

I am learning Linux for work, so am still a bit rusty on the edges. I need to change the folder permission of the directory /opt, and I know in Linux, you do the following: chmod 775 /opt I get a ...
2
votes
2answers
2k views

.sh file cannot be executed without explicitly calling sh

This problem has bugged me so much and I can't find a solution. Sorry in advance if it is a newbie question. Let's say I have a file called run.sh that contains: #! /bin/sh -x x-www-browser ...