# Permissions in Linux..!
**R** → Read or List
**W** → Write → Create or Delete
**X** → Enter Into Directory, Execute an Executable file.
RWX -
R → 4
W → 2
X → 1
2^0
2^1
2^2
**User Types:**
- **User (Owner)** → The creator of the file/directory.
- **Group** → Users belonging to the same group.
- **Others** → All other users.
**Read Access Includes:**
- Read and Execute
**Write Access Includes:**
- Read and Execute
**Example Permissions for a File Named "student"**
- **Owner:** `rwx` (Full permissions)
- **Group:** `rwx` (Full permissions)
- **Others:** `r_x` (Read and execute, no write permission)
**Create a Directory and Check Permissions**
Command: `mkdir /test`
Command: `ls -ld /test`
- Lists directory with long listing format to check permissions.
**Modify Permissions for Others**
Command: `chmod o-x /test`
- Removes execute permission for others.
Command: `chmod o+x /test`
- Adds execute permission for others.
### Sticky Bit
- Used on directories with full permissions to restrict file deletion.
- Prevents users from deleting files they don’t own.
**Apply Sticky Bit**
Command: `chmod 1777 /test`
- Allows everyone to create files but only the owner can delete their own files.
**Check Sticky Bit in Long Listing Format**
- `T + x = t` which appears in `ls -l` output.
**Remove or Add Sticky Bit**
Command: `chmod o+t /test`
- Adds the sticky bit.
Command: `chmod o-t /test`
- Removes the sticky bit.
**Set Full Permissions with Sticky Bit**
Command: `chmod 0777 /test`
- Grants full permissions to all users (use with caution).