chmod 004 Permission Explained
Summary: chmod 004 gives the owner no access, the group no access, and everyone else read.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 0 | |||
| Group (g) | 0 | |||
| Others (o) | 4 |
chmod 004 filename
chmod 004 Breakdown
| Class | Digit | Symbolic | On a file | On a directory |
|---|---|---|---|---|
| Owner (u) | 0 |
--- |
No access | Cannot list, enter, or modify |
| Group (g) | 0 |
--- |
No access | Cannot list, enter, or modify |
| Others (o) | 4 |
r-- |
Read only | Can list names, but not enter |
Is chmod 004 Safe?
Low Risk
- 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
004 is uncommon in standard Linux setups. The closest widely used permission is chmod 000.
chmod 004 Command Examples
# Apply using octal mode
chmod 004 filename
# Apply using equivalent symbolic mode
chmod u=,g=,o=r filename
# Recursive command warning:
chmod -R 004 /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 004 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
-------r-- 1 alice staff 1024 Jan 15 10:00 example.txtumask Relationship
A umask of 773 makes new directories 004 and new files 004. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 004 mean?
chmod 004 gives the owner no access, the group no access, and everyone else read. In octal notation, the owner receives 0 (no access), the group receives 0 (no access), and others receive 4 (read).
Is chmod 004 safe?
chmod 004 is classified as Low Risk. Any user can read this file — never use it for secrets such as keys or .env files.
What is chmod 004 in symbolic notation?
In symbolic notation, chmod 004 is represented as ------r--. You can apply this permission using the equivalent symbolic command "chmod u=,g=,o=r filename".
Related Permissions
Change one bit: