chmod 637 Permission Explained
Summary: chmod 637 gives the owner read/write, the group write/execute, and everyone else read/write/execute.
| Class | Read (4) | Write (2) | Execute (1) | Octal |
|---|---|---|---|---|
| Owner (u) | 6 | |||
| Group (g) | 3 | |||
| Others (o) | 7 |
chmod 637 filename
chmod 637 Breakdown
| Class | Digit | Symbolic | On a file | On a directory |
|---|---|---|---|---|
| Owner (u) | 6 |
rw- |
Read and write | Can list names, cannot enter |
| Group (g) | 3 |
-wx |
Write and execute | Can enter and create/delete files, but not list |
| Others (o) | 7 |
rwx |
Full access | Full access: list, enter, create, delete |
Is chmod 637 Safe?
Critical Risk
- Anyone on the system can modify or replace this file.
- Every member of the group can modify this file.
- 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
637 is uncommon in standard Linux setups. The closest widely used permission is chmod 777.
chmod 637 Command Examples
# Apply using octal mode
chmod 637 filename
# Apply using equivalent symbolic mode
chmod u=rw,g=wx,o=rwx filename
# Recursive command warning:
chmod -R 637 /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 637 {} +
# Verify permissions
stat -c '%a %A %n' filename # Linux
stat -f '%Lp %Sp %N' filename # macOS
# Example ls -l output:
-rw--wxrwx 1 alice staff 1024 Jan 15 10:00 example.txtumask Relationship
A umask of 140 makes new directories 637. Test umask values with our interactive Umask Calculator.
Frequently Asked Questions
What does chmod 637 mean?
chmod 637 gives the owner read/write, the group write/execute, and everyone else read/write/execute. In octal notation, the owner receives 6 (read/write), the group receives 3 (write/execute), and others receive 7 (read/write/execute).
Is chmod 637 safe?
chmod 637 is classified as Critical Risk. Anyone on the system can modify or replace this file.
What is chmod 637 in symbolic notation?
In symbolic notation, chmod 637 is represented as rw--wxrwx. You can apply this permission using the equivalent symbolic command "chmod u=rw,g=wx,o=rwx filename".
Related Permissions
Change one bit: