chmod 770 Permission Explained: Group-Private Directory

Octal

770

Symbolic

rwxrwx---

Binary

111 111 000

Risk Level

Moderate

Summary: Owner and group have full control; others have no access.

Class	Read (4)	Write (2)	Execute (1)	Octal
Owner (u)				7
Group (g)				7
Others (o)				0

setuid (4) setgid (2) sticky bit (1)

Octal

Symbolic

Target File / Path

-R Recursive -v Verbose

770

rwxrwx---

Owner: read/write/execute · Group: read/write/execute · Others: no access

chmod 770 filename

Moderate Every member of the group can modify this file.

View the full chmod 770 guide →

chmod 770 Breakdown

Class	Digit	Symbolic	On a file	On a directory
Owner (u)	`7`	`rwx`	Full access	Full access: list, enter, create, delete
Group (g)	`7`	`rwx`	Full access	Full access: list, enter, create, delete
Others (o)	`0`	`---`	No access	Cannot list, enter, or modify

Is chmod 770 Safe?

Moderate

Every member of the group can modify this file.

When not to use it

Web document roots when public web traffic must be served directly

Common Use Cases

Confidential team directories within corporate internal file servers
Backend data directories accessible only to service accounts and developers

chmod 770 Command Examples

# Apply using octal mode
chmod 770 filename

# Apply using equivalent symbolic mode
chmod u=rwx,g=rwx,o= filename

# Recursive command warning:
chmod -R 770 /path/to/dir
# Note: -R applies the same mode to files and directories. Use find to treat them separately:
find /path/to/dir -type d -exec chmod 770 {} +

# Verify permissions
stat -c '%a %A %n' filename    # Linux
stat -f '%Lp %Sp %N' filename   # macOS

# Example ls -l output:
-rwxrwx--- 1 alice staff 1024 Jan 15 10:00 example.txt

umask Relationship

A umask of 007 makes new directories 770. Test umask values with our interactive Umask Calculator.

Frequently Asked Questions

What does chmod 770 mean?

Owner and group have full control; others have no access. In octal notation, the owner receives 7 (read/write/execute), the group receives 7 (read/write/execute), and others receive 0 (no access).

Is chmod 770 safe?

chmod 770 is classified as Moderate. Every member of the group can modify this file.

What is chmod 770 in symbolic notation?

In symbolic notation, chmod 770 is represented as rwxrwx---. You can apply this permission using the equivalent symbolic command "chmod u=rwx,g=rwx,o= filename".