chmod 663 Permission Explained
Summary: chmod 663 gives the owner read/write, the group read/write, and everyone else write/execute.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 6 | |||
| Group (g) | 6 | |||
| Others (o) | 3 |
chmod 663 filename
chmod 663 Breakdown
| Class | Digit | Symbolic | On a file | On a directory |
|---|---|---|---|---|
| Owner (u) | 6 |
rw- |
Read and write | Can list names, cannot enter |
| Group (g) | 6 |
rw- |
Read and write | Can list names, cannot enter |
| Others (o) | 3 |
-wx |
Write and execute | Can enter and create/delete files, but not list |
Is chmod 663 Safe?
Critical Risk
- Anyone on the system can modify or replace this file.
- Every member of the group can modify this file.
- Unusual: a lower class has permissions the class above it lacks.
Common Use Cases
663 is uncommon in standard Linux setups. The closest widely used permission is chmod 666.
chmod 663 Command Examples
# Apply using octal mode
chmod 663 filename
# Apply using equivalent symbolic mode
chmod u=rw,g=rw,o=wx filename
# Recursive command warning:
chmod -R 663 /path/to/dir
# Note: -R applies the same mode to files and directories. Use find to treat them separately:
find /path/to/dir -type f -exec chmod 663 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
-rw-rw--wx 1 alice staff 1024 Jan 15 10:00 example.txtumask Relationship
A umask of 114 makes new directories 663. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 663 mean?
chmod 663 gives the owner read/write, the group read/write, and everyone else write/execute. In octal notation, the owner receives 6 (read/write), the group receives 6 (read/write), and others receive 3 (write/execute).
Is chmod 663 safe?
chmod 663 is classified as Critical Risk. Anyone on the system can modify or replace this file.
What is chmod 663 in symbolic notation?
In symbolic notation, chmod 663 is represented as rw-rw--wx. You can apply this permission using the equivalent symbolic command "chmod u=rw,g=rw,o=wx filename".
Related Permissions
Change one bit: