chmod 051 Permission Explained
Summary: chmod 051 gives the owner no access, the group read/execute, and everyone else execute.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 0 | |||
| Group (g) | 5 | |||
| Others (o) | 1 |
chmod 051 filename
chmod 051 Breakdown
| Class | Digit | Symbolic | On a file | On a directory |
|---|---|---|---|---|
| Owner (u) | 0 |
--- |
No access | Cannot list, enter, or modify |
| Group (g) | 5 |
r-x |
Read and execute | Can list and enter |
| Others (o) | 1 |
--x |
Execute only | Can enter (cd) but not list contents |
Is chmod 051 Safe?
Low Risk
- 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
051 is uncommon in standard Linux setups. The closest widely used permission is chmod 555.
chmod 051 Command Examples
# Apply using octal mode
chmod 051 filename
# Apply using equivalent symbolic mode
chmod u=,g=rx,o=x filename
# Recursive command warning:
chmod -R 051 /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 051 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
----r-x--x 1 alice staff 1024 Jan 15 10:00 example.txtumask Relationship
A umask of 726 makes new directories 051. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 051 mean?
chmod 051 gives the owner no access, the group read/execute, and everyone else execute. In octal notation, the owner receives 0 (no access), the group receives 5 (read/execute), and others receive 1 (execute).
Is chmod 051 safe?
chmod 051 is classified as Low Risk. Even the owner cannot modify this file without changing permissions first.
What is chmod 051 in symbolic notation?
In symbolic notation, chmod 051 is represented as ---r-x--x. You can apply this permission using the equivalent symbolic command "chmod u=,g=rx,o=x filename".
Related Permissions
Change one bit: