chmod 140 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

140

Symbolic

--xr-----

Binary

001 100 000

Risk Level

Low Risk

Summary: chmod 140 gives the owner execute, the group read, and everyone else no access.

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

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

Octal

Symbolic

Target File / Path

-R Recursive -v Verbose

140

--xr-----

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

chmod 140 filename

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

View the full chmod 140 guide →

chmod 140 Breakdown

Class	Digit	Symbolic	On a file	On a directory
Owner (u)	`1`	`--x`	Execute only	Can enter (cd) but not list contents
Group (g)	`4`	`r--`	Read only	Can list names, but not enter
Others (o)	`0`	`---`	No access	Cannot list, enter, or modify

Is chmod 140 Safe?

Low Risk

Even the owner cannot modify this file without changing permissions first.
Scripts need read permission to run; only compiled binaries can be executed without it.
Unusual: a lower class has permissions the class above it lacks.

Common Use Cases

140 is uncommon in standard Linux setups. The closest widely used permission is chmod 740.

chmod 140 Command Examples

# Apply using octal mode
chmod 140 filename

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

# Recursive command warning:
chmod -R 140 /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 140 {} +

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

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

umask Relationship

A umask of 637 makes new directories 140. Test umask values with our interactive Umask Calculator.

Frequently Asked Questions

What does chmod 140 mean?

chmod 140 gives the owner execute, the group read, and everyone else no access. In octal notation, the owner receives 1 (execute), the group receives 4 (read), and others receive 0 (no access).

Is chmod 140 safe?

chmod 140 is classified as Low Risk. Even the owner cannot modify this file without changing permissions first.

What is chmod 140 in symbolic notation?

In symbolic notation, chmod 140 is represented as --xr-----. You can apply this permission using the equivalent symbolic command "chmod u=x,g=r,o= filename".