chmod 504 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

504

Symbolic

r-x---r--

Binary

101 000 100

Risk Level

Low Risk

Summary: chmod 504 gives the owner read/execute, the group no access, and everyone else read.

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

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

Octal

Symbolic

Target File / Path

-R Recursive -v Verbose

504

r-x---r--

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

chmod 504 filename

Low Risk Any user can read this file — never use it for secrets such as keys or .env files.

View the full chmod 504 guide →

chmod 504 Breakdown

Class	Digit	Symbolic	On a file	On a directory
Owner (u)	`5`	`r-x`	Read and execute	Can list and enter
Group (g)	`0`	`---`	No access	Cannot list, enter, or modify
Others (o)	`4`	`r--`	Read only	Can list names, but not enter

Is chmod 504 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

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

chmod 504 Command Examples

# Apply using octal mode
chmod 504 filename

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

# Recursive command warning:
chmod -R 504 /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 504 {} +

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

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

umask Relationship

A umask of 273 makes new directories 504. Test umask values with our interactive Umask Calculator.

Frequently Asked Questions

What does chmod 504 mean?

chmod 504 gives the owner read/execute, the group no access, and everyone else read. In octal notation, the owner receives 5 (read/execute), the group receives 0 (no access), and others receive 4 (read).

Is chmod 504 safe?

chmod 504 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 504 in symbolic notation?

In symbolic notation, chmod 504 is represented as r-x---r--. You can apply this permission using the equivalent symbolic command "chmod u=rx,g=,o=r filename".