How do you view file permissions?

I want to know how to see the permissions a particular file has. Which command should I type in the terminal? However, I don't want to change it.

4 Answers

If you want to see the the permission of a file you can use ls -l /path/to/file command.

For example

 ls -l acroread -rwxr-xr-x 1 10490 floppy 17242 May 8 2013 acroread

What does this mean ?

First - represents a regular file. It gives you a hint of the type of object it is. It can have following values.

• d (directory)
• c (character device)
• l (symlink)
• p (named pipe)
• s (socket)
• b (block device)
• D (door)
• - (regular file)

r represents read permission.
w represents write permission and
x represents executable permission.

First combination of rwx represents permission for the owner .
Second combination of rwx represents permission for the group .
Third combination of rwx represents permission for the other of the file.

Octal notation

Permission of file can also be represented in octal notation.
In octal notation

Read or r is represented by 4,
Write or w is represented by 2
Execute x is represented by 1.

Sum of these three is use to represent the permission.

stat command can be used to view file permission in octal notation

 stat -c "%a %n" /path/of/file

For example

 stat -c "%a %n" acroread 755 acroread

Here you can see

For owner it is 4+2+1=7 (111 in binary)
For group it is 4+0+1=5 (101 in binary) and
For other it is 4+0+1=5 (101 in binary).

You can use either long listing:

ls -l [filename]

Or stat:

stat [filename]

Stat is more comprehensive; it shows you the access, modify and change times, as well as Inode and size information, which may or may not be useful to you.

Regardless of your actually using ACL permissions, if you have the acl package installed, you can use getfacl <path> to get a pretty decent breakdown of permissions on that file.

$ getfacl /root/
# file: root/
# owner: root
# group: root
user::rwx
group::---
other::---

If you do use ACL permissions, it'll tell you about permissions that ls and stat just can't.

$ sudo setfacl -m u:oli:r /root
$ getfacl /root/
# file: root/
# owner: root
# group: root
user::rwxuser:oli:r--group::---
mask::r--
other::---

You can also see file permission by right-clicking the file and selecting properties and there you will find permissions.