chmod 156 Permission Explained
Summary: chmod 156 gives the owner execute, the group read/execute, and everyone else read/write.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 1 | |||
| Group (g) | 5 | |||
| Others (o) | 6 |
chmod 156 filename
chmod 156 Breakdown
| Class | Digit | Symbolic | On a file | On a directory |
|---|---|---|---|---|
| Owner (u) | 1 |
--x |
Execute only | Can enter (cd) but not list contents |
| Group (g) | 5 |
r-x |
Read and execute | Can list and enter |
| Others (o) | 6 |
rw- |
Read and write | Can list names, cannot enter |
Is chmod 156 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.
- Scripts need read permission to run; only compiled binaries can be executed without it.
- Unusual: a lower class has permissions the class above it lacks.
Common Use Cases
156 is uncommon in standard Linux setups. The closest widely used permission is chmod 555.
chmod 156 Command Examples
# Apply using octal mode
chmod 156 filename
# Apply using equivalent symbolic mode
chmod u=x,g=rx,o=rw filename
# Recursive command warning:
chmod -R 156 /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 156 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
---xr-xrw- 1 alice staff 1024 Jan 15 10:00 example.txtumask Relationship
A umask of 621 makes new directories 156. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 156 mean?
chmod 156 gives the owner execute, the group read/execute, and everyone else read/write. In octal notation, the owner receives 1 (execute), the group receives 5 (read/execute), and others receive 6 (read/write).
Is chmod 156 safe?
chmod 156 is classified as Critical Risk. Anyone on the system can modify or replace this file.
What is chmod 156 in symbolic notation?
In symbolic notation, chmod 156 is represented as --xr-xrw-. You can apply this permission using the equivalent symbolic command "chmod u=x,g=rx,o=rw filename".
Related Permissions
Change one bit: