chmod 520 Permission Explained

Notice: This is an unusual permission set: some classes have more access than the class above them. It is rarely correct in practice.

Octal

520

Symbolic

r-x-w----

Binary

101 010 000

Risk Level

Moderate

Summary: chmod 520 gives the owner read/execute, the group write, and everyone else no access.

Class	Read (4)	Write (2)	Execute (1)	Octal
Owner (u)				5
Group (g)				2
Others (o)				0

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

Octal

Symbolic

Target File / Path

-R Recursive -v Verbose

520

r-x-w----

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

chmod 520 filename

Moderate Every member of the group can modify this file.

View the full chmod 520 guide →

chmod 520 Breakdown

Class	Digit	Symbolic	On a file	On a directory
Owner (u)	`5`	`r-x`	Read and execute	Can list and enter
Group (g)	`2`	`-w-`	Write only (rarely useful)	No practical effect without x
Others (o)	`0`	`---`	No access	Cannot list, enter, or modify

Is chmod 520 Safe?

Moderate

Every member of the group can modify this file.
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

520 is uncommon in standard Linux setups. The closest widely used permission is chmod 500.

chmod 520 Command Examples

# Apply using octal mode
chmod 520 filename

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

# Recursive command warning:
chmod -R 520 /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 520 {} +

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

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

umask Relationship

A umask of 257 makes new directories 520. Test umask values with our interactive Umask Calculator.

Frequently Asked Questions

What does chmod 520 mean?

chmod 520 gives the owner read/execute, the group write, and everyone else no access. In octal notation, the owner receives 5 (read/execute), the group receives 2 (write), and others receive 0 (no access).

Is chmod 520 safe?

chmod 520 is classified as Moderate. Every member of the group can modify this file.

What is chmod 520 in symbolic notation?

In symbolic notation, chmod 520 is represented as r-x-w----. You can apply this permission using the equivalent symbolic command "chmod u=rx,g=w,o= filename".