LINUX COMMAND ATLAS · COMMAND GUIDE

Linux chmod command

Change file permissions. This example grants the owner execute permission.

GNU Coreutils

Syntax

Command form

chmod [OPTION]... MODE FILE...

Common options

7 options

Option	What it does
`MODE (symbolic)`	Use forms such as u+x, go-w or a=rx.
`MODE (numeric)`	Use octal digits such as 640 or 755.
`-R, --recursive`	Change permissions recursively (directories and contents).
`-v, --verbose`	Report every processed file.
`-c, --changes`	Report only files whose permissions changed.
`-f, --silent`	Suppress most error messages.
`--reference=FILE`	Use FILE's mode instead of MODE.

Usage examples

2 examples

Change file permissions. This example grants the owner execute permission.

chmod u+x ./script.sh

Set owner read/write and group read permissions.

chmod 640 ./secrets.txt

Notes

Recursive permission changes can expose or break files. Avoid applying a single mode blindly to mixed files and directories; inspect with ls -l first.

Read the manual: GNU Coreutils All commands