chmod 045 Permission Explained
Summary: chmod 045 gives the owner no access, the group read, and everyone else read/execute.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 0 | |||
| Group (g) | 4 | |||
| Others (o) | 5 |
chmod 045 filename
chmod 045 Breakdown
| Class | Digit | Symbolic | On a file | On a directory |
|---|---|---|---|---|
| Owner (u) | 0 |
--- |
No access | Cannot list, enter, or modify |
| Group (g) | 4 |
r-- |
Read only | Can list names, but not enter |
| Others (o) | 5 |
r-x |
Read and execute | Can list and enter |
Is chmod 045 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
045 is uncommon in standard Linux setups. The closest widely used permission is chmod 444.
chmod 045 Command Examples
# Apply using octal mode
chmod 045 filename
# Apply using equivalent symbolic mode
chmod u=,g=r,o=rx filename
# Recursive command warning:
chmod -R 045 /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 045 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
----r--r-x 1 alice staff 1024 Jan 15 10:00 example.txtumask Relationship
A umask of 732 makes new directories 045. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 045 mean?
chmod 045 gives the owner no access, the group read, and everyone else read/execute. In octal notation, the owner receives 0 (no access), the group receives 4 (read), and others receive 5 (read/execute).
Is chmod 045 safe?
chmod 045 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 045 in symbolic notation?
In symbolic notation, chmod 045 is represented as ---r--r-x. You can apply this permission using the equivalent symbolic command "chmod u=,g=r,o=rx filename".
Related Permissions
Change one bit: