What are Permissions?
Explore how file and directory permissions in Linux control access and modification rights. This lesson helps you understand the types of permissions—read, write, execute—and how they are represented symbolically and numerically to manage user access effectively.
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In Linux, each file or directory follows certain set of rules and restrictions regarding who can access the file and change its content. These rules or access modes are commonly referred as permissions in Bash. Permissions are sometimes very useful as it gives us the benefit of hiding certain things from other users or make them non-editable for them.
Types of Permissions:
Based on the kind of actions a user can perform on a file, the three basic type of permissions are:
- Read
- Write
- Execute
Symbolical Permissions:
| Mode | Meaning |
|---|---|
| r | Read the file |
| w | Write/Delete the file |
| x | Execute the file or search the directory |
Numerical Permissions:
Given below is a list of numerical modes which can be changed for the owner, group users, and everyone else. A symbolical equivalent is also mentioned in the next column.
| Mode | Meaning |
|---|---|
| 0 | 000 -> --- -> None |
| 1 | 001 -> --x -> Execute Only |
| 2 | 010 -> -w- -> Write only |
| 3 | 011 -> -wx -> Write and Execute |
| 4 | 100 -> r-- -> Read only |
| 5 | 101 -> r-x -> Read and Execute |
| 6 | 110 -> rw- -> Read and Write |
| 7 | 111 -> rwx -> Read, Write & Execute |