chmod 457 Permission Explained
Summary: chmod 457 gives the owner read, the group read/execute, and everyone else read/write/execute.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 4 | |||
| Group (g) | 5 | |||
| Others (o) | 7 |
chmod 457 filename
chmod 457 Breakdown
| Class | Digit | Symbolic | On a file | On a directory |
|---|---|---|---|---|
| Owner (u) | 4 |
r-- |
Read only | Can list names, but not enter |
| Group (g) | 5 |
r-x |
Read and execute | Can list and enter |
| Others (o) | 7 |
rwx |
Full access | Full access: list, enter, create, delete |
Is chmod 457 Safe?
Critical Risk
- Anyone on the system can modify or replace this file.
- 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
457 is uncommon in standard Linux setups. The closest widely used permission is chmod 555.
chmod 457 Command Examples
# Apply using octal mode
chmod 457 filename
# Apply using equivalent symbolic mode
chmod u=r,g=rx,o=rwx filename
# Recursive command warning:
chmod -R 457 /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 457 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
-r--r-xrwx 1 alice staff 1024 Jan 15 10:00 example.txtumask Relationship
A umask of 320 makes new directories 457. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 457 mean?
chmod 457 gives the owner read, the group read/execute, and everyone else read/write/execute. In octal notation, the owner receives 4 (read), the group receives 5 (read/execute), and others receive 7 (read/write/execute).
Is chmod 457 safe?
chmod 457 is classified as Critical Risk. Anyone on the system can modify or replace this file.
What is chmod 457 in symbolic notation?
In symbolic notation, chmod 457 is represented as r--r-xrwx. You can apply this permission using the equivalent symbolic command "chmod u=r,g=rx,o=rwx filename".
Related Permissions
Change one bit: