Chapter 10: File System Security

Commands:

Command Description Examples
chmod Change File or Directory Permissions Deny execute permission to everyone:
$ chmod a-x filename

Allow only read permission to everyone:
$ chmod 444 file1

Make a file readable and writable by the group and others:
$ chmod go+rw file2

groups displays all the groups a user is a member of. $ groups user1 user2
user1 : staff
user2 : staff