chmod 516 Permission Explained
Summary: chmod 516 gives the owner read/execute, the group execute, and everyone else read/write.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 5 | |||
| Group (g) | 1 | |||
| Others (o) | 6 |
chmod 516 filename
chmod 516 Breakdown
| Class | Digit | Symbolic | On a file | On a directory |
|---|---|---|---|---|
| Owner (u) | 5 |
r-x |
Read and execute | Can list and enter |
| Group (g) | 1 |
--x |
Execute only | Can enter (cd) but not list contents |
| Others (o) | 6 |
rw- |
Read and write | Can list names, cannot enter |
Is chmod 516 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
516 is uncommon in standard Linux setups. The closest widely used permission is chmod 555.
chmod 516 Command Examples
# Apply using octal mode
chmod 516 filename
# Apply using equivalent symbolic mode
chmod u=rx,g=x,o=rw filename
# Recursive command warning:
chmod -R 516 /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 516 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
-r-x--xrw- 1 alice staff 1024 Jan 15 10:00 example.txtumask Relationship
A umask of 261 makes new directories 516. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 516 mean?
chmod 516 gives the owner read/execute, the group execute, and everyone else read/write. In octal notation, the owner receives 5 (read/execute), the group receives 1 (execute), and others receive 6 (read/write).
Is chmod 516 safe?
chmod 516 is classified as Critical Risk. Anyone on the system can modify or replace this file.
What is chmod 516 in symbolic notation?
In symbolic notation, chmod 516 is represented as r-x--xrw-. You can apply this permission using the equivalent symbolic command "chmod u=rx,g=x,o=rw filename".
Related Permissions
Change one bit: