chmod 403 Permission Explained
Summary: chmod 403 gives the owner read, the group no access, and everyone else write/execute.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 4 | |||
| Group (g) | 0 | |||
| Others (o) | 3 |
chmod 403 filename
chmod 403 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) | 3 |
-wx |
Write and execute | Can enter and create/delete files, but not list |
Is chmod 403 Safe?
Critical Risk
- Anyone on the system can modify or replace this file.
- 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
403 is uncommon in standard Linux setups. The closest widely used permission is chmod 400.
chmod 403 Command Examples
# Apply using octal mode
chmod 403 filename
# Apply using equivalent symbolic mode
chmod u=r,g=,o=wx filename
# Recursive command warning:
chmod -R 403 /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 403 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
-r------wx 1 alice staff 1024 Jan 15 10:00 example.txtumask Relationship
A umask of 374 makes new directories 403. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 403 mean?
chmod 403 gives the owner read, the group no access, and everyone else write/execute. In octal notation, the owner receives 4 (read), the group receives 0 (no access), and others receive 3 (write/execute).
Is chmod 403 safe?
chmod 403 is classified as Critical Risk. Anyone on the system can modify or replace this file.
What is chmod 403 in symbolic notation?
In symbolic notation, chmod 403 is represented as r------wx. You can apply this permission using the equivalent symbolic command "chmod u=r,g=,o=wx filename".
Related Permissions
Change one bit: