chmod 121 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

121

Symbolic

--x-w---x

Binary

001 010 001

Risk Level

Moderate

Summary: chmod 121 gives the owner execute, the group write, and everyone else execute.

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

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

Octal

Symbolic

Target File / Path

-R Recursive -v Verbose

121

--x-w---x

Owner: execute · Group: write · Others: execute

chmod 121 filename

Moderate Every member of the group can modify this file.

View the full chmod 121 guide →

chmod 121 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)	`2`	`-w-`	Write only (rarely useful)	No practical effect without x
Others (o)	`1`	`--x`	Execute only	Can enter (cd) but not list contents

Is chmod 121 Safe?

Moderate

Every member of the group can modify this file.
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

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

chmod 121 Command Examples

# Apply using octal mode
chmod 121 filename

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

# Recursive command warning:
chmod -R 121 /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 121 {} +

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

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

umask Relationship

A umask of 656 makes new directories 121. Test umask values with our interactive Umask Calculator.

Frequently Asked Questions

What does chmod 121 mean?

chmod 121 gives the owner execute, the group write, and everyone else execute. In octal notation, the owner receives 1 (execute), the group receives 2 (write), and others receive 1 (execute).

Is chmod 121 safe?

chmod 121 is classified as Moderate. Every member of the group can modify this file.

What is chmod 121 in symbolic notation?

In symbolic notation, chmod 121 is represented as --x-w---x. You can apply this permission using the equivalent symbolic command "chmod u=x,g=w,o=x filename".