PERMISSION ATTRIBUTES
Symbolic Mode
symbolic mode in Linux refers to a way of changing file or directory permissions using human-readable symbols with the "Chmod" command. There are three parts to it:
1) Who: Represents the user (owner), group, or others (public).
- u for user/owner.
- g for group.
- o for others/public.
2) Operator: Indicates whether to add, remove, or set permissions.
- + adds permissions.
- - removes permissions.
- = sets permissions.
3) Permission: Denotes the specific permission to add, remove, or set.
- r for read.
- w for write.
- x for execute.
Absolute Mode
In Linux, the absolute mode, also known as octal mode, is another way of representing and setting file permissions using numeric values. Each permission is assigned a numeric value:
- Read (r) is represented by 4.
- Write (w) is represented by 2.
- Execute (x) is represented by 1.
You add these values to represent different combinations of permissions. The total is a three-digit number, where each digit corresponds to the permissions for the owner, group, and others.
Examples include
chmod 755 (full permissions for the owner, read/execute for group and others)
chmod 644 (read and write for the owner, read-only for group and others).
This method provides a concise numeric representation of who can do what with a file or directory.