chmod 251 Permission Explained
Summary: chmod 251 gives the owner write, the group read/execute, and everyone else execute.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 2 | |||
| Group (g) | 5 | |||
| Others (o) | 1 |
chmod 251 filename
chmod 251 Breakdown
| Class | Digit | Symbolic | On a file | On a directory |
|---|---|---|---|---|
| Owner (u) | 2 |
-w- |
Write only (rarely useful) | No practical effect without x |
| 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 251 Safe?
Low Risk
- Unusual: a lower class has permissions the class above it lacks.
Common Use Cases
251 is uncommon in standard Linux setups. The closest widely used permission is chmod 755.
chmod 251 Command Examples
# Apply using octal mode
chmod 251 filename
# Apply using equivalent symbolic mode
chmod u=w,g=rx,o=x filename
# Recursive command warning:
chmod -R 251 /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 251 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
--w-r-x--x 1 alice staff 1024 Jan 15 10:00 example.txtumask Relationship
A umask of 526 makes new directories 251. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 251 mean?
chmod 251 gives the owner write, the group read/execute, and everyone else execute. In octal notation, the owner receives 2 (write), the group receives 5 (read/execute), and others receive 1 (execute).
Is chmod 251 safe?
chmod 251 is classified as Low Risk. Unusual: a lower class has permissions the class above it lacks.
What is chmod 251 in symbolic notation?
In symbolic notation, chmod 251 is represented as -w-r-x--x. You can apply this permission using the equivalent symbolic command "chmod u=w,g=rx,o=x filename".
Related Permissions
Change one bit: