chmod 500 Permission Explained: Owner Read/Execute Only

Octal

500

Symbolic

r-x------

Binary

101 000 000

Risk Level

Restrictive

Summary: Owner can read and run; nobody can write.

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

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

Octal

Symbolic

Target File / Path

-R Recursive -v Verbose

500

r-x------

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

chmod 500 filename

Restrictive Even the owner cannot modify this file without changing permissions first.

View the full chmod 500 guide →

chmod 500 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)	`0`	`---`	No access	Cannot list, enter, or modify

Is chmod 500 Safe?

Restrictive

Even the owner cannot modify this file without changing permissions first.

When not to use it

Shared tools that coworkers need to execute or inspect

Common Use Cases

Locked-down personal maintenance scripts to guard against accidental editing
Private read-only directories

chmod 500 Command Examples

# Apply using octal mode
chmod 500 filename

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

# Recursive command warning:
chmod -R 500 /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 500 {} +

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

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

umask Relationship

A umask of 277 makes new directories 500. Test umask values with our interactive Umask Calculator.

Frequently Asked Questions

What does chmod 500 mean?

Owner can read and run; nobody can write. In octal notation, the owner receives 5 (read/execute), the group receives 0 (no access), and others receive 0 (no access).

Is chmod 500 safe?

chmod 500 is classified as Restrictive. Even the owner cannot modify this file without changing permissions first.

What is chmod 500 in symbolic notation?

In symbolic notation, chmod 500 is represented as r-x------. You can apply this permission using the equivalent symbolic command "chmod u=rx,g=,o= filename".