chmod 506 Permission Explained
Summary: chmod 506 gives the owner read/execute, the group no access, and everyone else read/write.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 5 | |||
| Group (g) | 0 | |||
| Others (o) | 6 |
chmod 506 filename
chmod 506 Breakdown
| Class | Digit | Symbolic | On a file | On a directory |
|---|---|---|---|---|
| Owner (u) | 5 |
r-x |
Read and execute | Can list and enter |
| Group (g) | 0 |
--- |
No access | Cannot list, enter, or modify |
| Others (o) | 6 |
rw- |
Read and write | Can list names, cannot enter |
Is chmod 506 Safe?
Critical Risk
- Anyone on the system can modify or replace 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
506 is uncommon in standard Linux setups. The closest widely used permission is chmod 500.
chmod 506 Command Examples
# Apply using octal mode
chmod 506 filename
# Apply using equivalent symbolic mode
chmod u=rx,g=,o=rw filename
# Recursive command warning:
chmod -R 506 /path/to/dir
# Note: -R applies the same mode to files and directories. Use find to treat them separately:
find /path/to/dir -type d -exec chmod 506 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
-r-x---rw- 1 alice staff 1024 Jan 15 10:00 example.txt
umask Relationship
A umask of 271 makes new directories 506. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 506 mean?
chmod 506 gives the owner read/execute, the group no access, and everyone else read/write. In octal notation, the owner receives 5 (read/execute), the group receives 0 (no access), and others receive 6 (read/write).
Is chmod 506 safe?
chmod 506 is classified as Critical Risk. Anyone on the system can modify or replace this file.
What is chmod 506 in symbolic notation?
In symbolic notation, chmod 506 is represented as r-x---rw-. You can apply this permission using the equivalent symbolic command "chmod u=rx,g=,o=rw filename".
Related Permissions
Change one bit: