chmod 405 Permission Explained
Summary: chmod 405 gives the owner read, the group no access, and everyone else read/execute.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 4 | |||
| Group (g) | 0 | |||
| Others (o) | 5 |
chmod 405 filename
chmod 405 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) | 5 |
r-x |
Read and execute | Can list and enter |
Is chmod 405 Safe?
Low Risk
- 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
405 is uncommon in standard Linux setups. The closest widely used permission is chmod 400.
chmod 405 Command Examples
# Apply using octal mode
chmod 405 filename
# Apply using equivalent symbolic mode
chmod u=r,g=,o=rx filename
# Recursive command warning:
chmod -R 405 /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 405 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
-r-----r-x 1 alice staff 1024 Jan 15 10:00 example.txtumask Relationship
A umask of 372 makes new directories 405. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 405 mean?
chmod 405 gives the owner read, the group no access, and everyone else read/execute. In octal notation, the owner receives 4 (read), the group receives 0 (no access), and others receive 5 (read/execute).
Is chmod 405 safe?
chmod 405 is classified as Low Risk. Any user can read this file — never use it for secrets such as keys or .env files.
What is chmod 405 in symbolic notation?
In symbolic notation, chmod 405 is represented as r-----r-x. You can apply this permission using the equivalent symbolic command "chmod u=r,g=,o=rx filename".
Related Permissions
Change one bit: