Numeric (Octal)
Format: 3 or 4 digits (0-7)
- First digit: User permissions
- Second digit: Group permissions
- Third digit: Other permissions
Symbolic Notation
Format: File type + 9 permission characters
- File type:
-(file),d(directory),l(symlink) - r = read (4), w = write (2), x = execute (1), - = no permission
Permission Breakdown
User (Owner)
Read (4 | 100) -
Write (2 | 010) -
Execute (1 | 001) -
Binary: 000
Numeric: 0
Group
Read (4 | 100) -
Write (2 | 010) -
Execute (1 | 001) -
Binary: 000
Numeric: 0
Other (Everyone)
Read (4 | 100) -
Write (2 | 010) -
Execute (1 | 001) -
Binary: 000
Numeric: 0
Common Permissions
Files
- 644 -rw-r--r-- Standard file
- 600 -rw------- Private file
- 755 -rwxr-xr-x Executable
- 777 -rwxrwxrwx Full access
Directories
- 755 drwxr-xr-x Standard dir
- 700 drwx------ Private dir
- 775 drwxrwxr-x Shared dir
- 750 drwxr-x--- Group readable
What Do Permissions Mean?
For Files
Read (r)
Allows viewing and reading the file's contents. You can open and read the file, but not modify it.
Write (w)
Allows modifying the file's contents. You can edit, append to, or delete the contents of the file.
Execute (x)
Allows running the file as a program or script. Required for shell scripts, binaries, and executable files.
For Directories
Read (r)
Allows listing the directory's contents. You can see the names of files and subdirectories using commands like ls.
Write (w)
Allows creating, deleting, and renaming files within the directory. Requires execute permission to work properly.
Execute (x)
Allows entering the directory and accessing its files. Required to cd into the directory or access files inside it.