chmod

Change file permissions using symbolic or numeric modes.

Synopsis

chmod [options] mode file

Core Options

-R

Change permissions recursively.

--reference=FILE

Copy permissions from another file.

u/g/o/a

User, group, others, all (symbolic mode).

+/-/=

Add, remove, or set permissions.

Usage Examples

Numeric Mode

Set rwx for user, rx for group/others.

chmod 755 script.sh

Symbolic Mode

Add execute permission for user.

chmod u+x script.sh

Recursive

Make all files in a directory readable.

chmod -R a+r data/

Setgid Bit

New files inherit group in a directory.

chmod g+s shared/

Copy Permissions

Match permissions of another file.

chmod --reference=template.sh deploy.sh
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