chmod 177 Permission Explained
Summary: chmod 177 gives the owner execute, the group read/write/execute, and everyone else read/write/execute.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 1 | |||
| Group (g) | 7 | |||
| Others (o) | 7 |
chmod 177 filename
chmod 177 Breakdown
| Class | Digit | Symbolic | On a file | On a directory |
|---|---|---|---|---|
| Owner (u) | 1 |
--x |
Execute only | Can enter (cd) but not list contents |
| Group (g) | 7 |
rwx |
Full access | Full access: list, enter, create, delete |
| Others (o) | 7 |
rwx |
Full access | Full access: list, enter, create, delete |
Is chmod 177 Safe?
Critical Risk
- Anyone on the system can modify or replace this file.
- Every member of the group can modify 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.
- Scripts need read permission to run; only compiled binaries can be executed without it.
- Unusual: a lower class has permissions the class above it lacks.
Common Use Cases
177 is uncommon in standard Linux setups. The closest widely used permission is chmod 777.
chmod 177 Command Examples
# Apply using octal mode
chmod 177 filename
# Apply using equivalent symbolic mode
chmod u=x,g=rwx,o=rwx filename
# Recursive command warning:
chmod -R 177 /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 177 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
---xrwxrwx 1 alice staff 1024 Jan 15 10:00 example.txtumask Relationship
A umask of 600 makes new directories 177. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 177 mean?
chmod 177 gives the owner execute, the group read/write/execute, and everyone else read/write/execute. In octal notation, the owner receives 1 (execute), the group receives 7 (read/write/execute), and others receive 7 (read/write/execute).
Is chmod 177 safe?
chmod 177 is classified as Critical Risk. Anyone on the system can modify or replace this file.
What is chmod 177 in symbolic notation?
In symbolic notation, chmod 177 is represented as --xrwxrwx. You can apply this permission using the equivalent symbolic command "chmod u=x,g=rwx,o=rwx filename".
Related Permissions
Change one bit: