chmod 077 Permission Explained
Summary: chmod 077 gives the owner no access, the group read/write/execute, and everyone else read/write/execute.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 0 | |||
| Group (g) | 7 | |||
| Others (o) | 7 |
chmod 077 filename
chmod 077 Breakdown
| Class | Digit | Symbolic | On a file | On a directory |
|---|---|---|---|---|
| Owner (u) | 0 |
--- |
No access | Cannot list, enter, or modify |
| 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 077 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.
- Unusual: a lower class has permissions the class above it lacks.
Common Use Cases
077 is uncommon in standard Linux setups. The closest widely used permission is chmod 777.
chmod 077 Command Examples
# Apply using octal mode
chmod 077 filename
# Apply using equivalent symbolic mode
chmod u=,g=rwx,o=rwx filename
# Recursive command warning:
chmod -R 077 /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 077 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
----rwxrwx 1 alice staff 1024 Jan 15 10:00 example.txtumask Relationship
A umask of 700 makes new directories 077. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 077 mean?
chmod 077 gives the owner no access, the group read/write/execute, and everyone else read/write/execute. In octal notation, the owner receives 0 (no access), the group receives 7 (read/write/execute), and others receive 7 (read/write/execute).
Is chmod 077 safe?
chmod 077 is classified as Critical Risk. Anyone on the system can modify or replace this file.
What is chmod 077 in symbolic notation?
In symbolic notation, chmod 077 is represented as ---rwxrwx. You can apply this permission using the equivalent symbolic command "chmod u=,g=rwx,o=rwx filename".
Related Permissions
Change one bit: