
In a multi-user environment, security of user and system data is important. Linux™ has three distinct classes:
r - read permission grants the ability to read a file.
w - write permission grants the ability to modify a file.
x - execute permission grants the ability to execute a file.
The list above shows the symbolic notation of each permission in bold text. Each permission also has an octal notation (is represented by digits from 0 to 7):
r - 4
w - 2
x - 1
To view permissions, open a terminal by going to → → → and then type
ls -l ~/
This will output a list of the directories and files in the current user's home directory. For example:
drwxr-xr-x 2 username usergroup 4096 2009-12-17 11:10 Documents
The first column, which contains drwxr-xr-x, can be interpreted as follows:
File Type | User Permissions | Group Permissions | Others Permissions |
---|---|---|---|
d - directory | rwx - read, write, and execute permissions for the user | r-x - read and execute permissions for the group | r-x - read and execute permissions for all others |