How do you view file permissions?
If you want to see the the permission of a file you can use ls -l /path/to/file command.
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.
c (character device)
p (named pipe)
b (block device)
- (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.
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
stat -c "%a %n" 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).