- Add single permission to a file/directory
Changing permission to a single set. + symbol means adding permission.
For example, do the following to give execute permission for the user
irrespective of anything else:
$ chmod u+x filename
- Add multiple permission to a file/directory
Use comma to separate the multiple permission sets as shown below.
$ chmod u+r,g+x filename
- Remove permission from a file/directory
Following example removes read and write permission for the user.
$ chmod u-rx filename
- Change permission for all roles on a file/directory
Following example assigns execute privilege to user, group and others
(basically anybody can execute this file).
$ chmod a+x filename
- Make permission for a file same as another file (using reference)
If you want to change a file permission same as another file, use the
reference option as shown below. In this example, file2′s permission
will be set exactly same as file1′s permission.
$ chmod --reference=file1 file2
- Apply the permission to all the files under a directory recursively
Use option -R to change the permission recursively as shown below.
$ chmod -R 755 directory-name/
- Change execute permission only on the directories (files are not affected)
On a particular directory if you have multiple sub-directories and
files, the following command will assign execute permission only to
all the sub-directories in the current directory (not the files in the
current directory).
$ chmod u+X *