chmod 657 Permission Explained
Summary: chmod 657 gives the owner read/write, the group read/execute, and everyone else read/write/execute.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 6 | |||
| Group (g) | 5 | |||
| Others (o) | 7 |
chmod 657 filename
chmod 657 Breakdown
| Class | Digit | Symbolic | On a file | On a directory |
|---|---|---|---|---|
| Owner (u) | 6 |
rw- |
Read and write | Can list names, cannot enter |
| Group (g) | 5 |
r-x |
Read and execute | Can list and enter |
| Others (o) | 7 |
rwx |
Full access | Full access: list, enter, create, delete |
Is chmod 657 Safe?
Critical Risk
- Anyone on the system can modify or replace this file.
- Any user can read this file — never use it for secrets such as keys or .env files.
- Unusual: a lower class has permissions the class above it lacks.
Common Use Cases
657 is uncommon in standard Linux setups. The closest widely used permission is chmod 755.
chmod 657 Command Examples
# Apply using octal mode
chmod 657 filename
# Apply using equivalent symbolic mode
chmod u=rw,g=rx,o=rwx filename
# Recursive command warning:
chmod -R 657 /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 657 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
-rw-r-xrwx 1 alice staff 1024 Jan 15 10:00 example.txtumask Relationship
A umask of 120 makes new directories 657. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 657 mean?
chmod 657 gives the owner read/write, the group read/execute, and everyone else read/write/execute. In octal notation, the owner receives 6 (read/write), the group receives 5 (read/execute), and others receive 7 (read/write/execute).
Is chmod 657 safe?
chmod 657 is classified as Critical Risk. Anyone on the system can modify or replace this file.
What is chmod 657 in symbolic notation?
In symbolic notation, chmod 657 is represented as rw-r-xrwx. You can apply this permission using the equivalent symbolic command "chmod u=rw,g=rx,o=rwx filename".
Related Permissions
Change one bit: