chmod 557 Permission Explained
Summary: chmod 557 gives the owner read/execute, the group read/execute, and everyone else read/write/execute.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 5 | |||
| Group (g) | 5 | |||
| Others (o) | 7 |
chmod 557 filename
chmod 557 Breakdown
| Class | Digit | Symbolic | On a file | On a directory |
|---|---|---|---|---|
| Owner (u) | 5 |
r-x |
Read and execute | Can list and 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 557 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.
- Even the owner cannot modify this file without changing permissions first.
- Unusual: a lower class has permissions the class above it lacks.
Common Use Cases
557 is uncommon in standard Linux setups. The closest widely used permission is chmod 555.
chmod 557 Command Examples
# Apply using octal mode
chmod 557 filename
# Apply using equivalent symbolic mode
chmod u=rx,g=rx,o=rwx filename
# Recursive command warning:
chmod -R 557 /path/to/dir
# Note: -R applies the same mode to files and directories. Use find to treat them separately:
find /path/to/dir -type d -exec chmod 557 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
-r-xr-xrwx 1 alice staff 1024 Jan 15 10:00 example.txtumask Relationship
A umask of 220 makes new directories 557. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 557 mean?
chmod 557 gives the owner read/execute, the group read/execute, and everyone else read/write/execute. In octal notation, the owner receives 5 (read/execute), the group receives 5 (read/execute), and others receive 7 (read/write/execute).
Is chmod 557 safe?
chmod 557 is classified as Critical Risk. Anyone on the system can modify or replace this file.
What is chmod 557 in symbolic notation?
In symbolic notation, chmod 557 is represented as r-xr-xrwx. You can apply this permission using the equivalent symbolic command "chmod u=rx,g=rx,o=rwx filename".
Related Permissions
Change one bit: