chmod 123 Permission Explained
Summary: chmod 123 gives the owner execute, the group write, and everyone else write/execute.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 1 | |||
| Group (g) | 2 | |||
| Others (o) | 3 |
chmod 123 filename
chmod 123 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) | 2 |
-w- |
Write only (rarely useful) | No practical effect without x |
| Others (o) | 3 |
-wx |
Write and execute | Can enter and create/delete files, but not list |
Is chmod 123 Safe?
Critical Risk
- Anyone on the system can modify or replace this file.
- Every member of the group can modify this file.
- 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
123 is uncommon in standard Linux setups. The closest widely used permission is chmod 500.
chmod 123 Command Examples
# Apply using octal mode
chmod 123 filename
# Apply using equivalent symbolic mode
chmod u=x,g=w,o=wx filename
# Recursive command warning:
chmod -R 123 /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 123 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
---x-w--wx 1 alice staff 1024 Jan 15 10:00 example.txtumask Relationship
A umask of 654 makes new directories 123. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 123 mean?
chmod 123 gives the owner execute, the group write, and everyone else write/execute. In octal notation, the owner receives 1 (execute), the group receives 2 (write), and others receive 3 (write/execute).
Is chmod 123 safe?
chmod 123 is classified as Critical Risk. Anyone on the system can modify or replace this file.
What is chmod 123 in symbolic notation?
In symbolic notation, chmod 123 is represented as --x-w--wx. You can apply this permission using the equivalent symbolic command "chmod u=x,g=w,o=wx filename".
Related Permissions
Change one bit: