chmod 604 Permission Explained
Summary: chmod 604 gives the owner read/write, the group no access, and everyone else read.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 6 | |||
| Group (g) | 0 | |||
| Others (o) | 4 |
chmod 604 filename
chmod 604 Breakdown
| Class | Digit | Symbolic | On a file | On a directory |
|---|---|---|---|---|
| Owner (u) | 6 |
rw- |
Read and write | Can list names, cannot enter |
| Group (g) | 0 |
--- |
No access | Cannot list, enter, or modify |
| Others (o) | 4 |
r-- |
Read only | Can list names, but not enter |
Is chmod 604 Safe?
Low Risk
- Any user can read this file — never use it for secrets such as keys or .env files.
- Unusual: a lower class has permissions the class above it lacks.
Common Use Cases
604 is uncommon in standard Linux setups. The closest widely used permission is chmod 644.
chmod 604 Command Examples
# Apply using octal mode
chmod 604 filename
# Apply using equivalent symbolic mode
chmod u=rw,g=,o=r filename
# Recursive command warning:
chmod -R 604 /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 604 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
-rw----r-- 1 alice staff 1024 Jan 15 10:00 example.txtumask Relationship
A umask of 173 makes new directories 604 and new files 604. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 604 mean?
chmod 604 gives the owner read/write, the group no access, and everyone else read. In octal notation, the owner receives 6 (read/write), the group receives 0 (no access), and others receive 4 (read).
Is chmod 604 safe?
chmod 604 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 604 in symbolic notation?
In symbolic notation, chmod 604 is represented as rw----r--. You can apply this permission using the equivalent symbolic command "chmod u=rw,g=,o=r filename".
Related Permissions
Change one bit: