chmod 401 Permission Explained
Summary: chmod 401 gives the owner read, the group no access, and everyone else execute.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 4 | |||
| Group (g) | 0 | |||
| Others (o) | 1 |
chmod 401 filename
chmod 401 Breakdown
| Class | Digit | Symbolic | On a file | On a directory |
|---|---|---|---|---|
| Owner (u) | 4 |
r-- |
Read only | Can list names, but not enter |
| Group (g) | 0 |
--- |
No access | Cannot list, enter, or modify |
| Others (o) | 1 |
--x |
Execute only | Can enter (cd) but not list contents |
Is chmod 401 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
401 is uncommon in standard Linux setups. The closest widely used permission is chmod 400.
chmod 401 Command Examples
# Apply using octal mode
chmod 401 filename
# Apply using equivalent symbolic mode
chmod u=r,g=,o=x filename
# Recursive command warning:
chmod -R 401 /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 401 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
-r-------x 1 alice staff 1024 Jan 15 10:00 example.txtumask Relationship
A umask of 376 makes new directories 401. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 401 mean?
chmod 401 gives the owner read, the group no access, and everyone else execute. In octal notation, the owner receives 4 (read), the group receives 0 (no access), and others receive 1 (execute).
Is chmod 401 safe?
chmod 401 is classified as Low Risk. Even the owner cannot modify this file without changing permissions first.
What is chmod 401 in symbolic notation?
In symbolic notation, chmod 401 is represented as r-------x. You can apply this permission using the equivalent symbolic command "chmod u=r,g=,o=x filename".
Related Permissions
Change one bit: