Centos Permissions

View your current username

whoami

View your group membership

groups

Change Group

chgrp sys file1
chgrp -R sys Desktop

Chown changes ownership and group ownership of a file

chown user1.root file1
chown -R user1.root Desktop

A user who does not have the execute permission to a directory is prevented from listing the directory’s contents, adding and removing files, and working with files and subdirectories inside that directory, regardless of what permissions the user has to them. In short, a quick way to deny a user from accessing a directory and all of its contents in Linux is to take away the execute per- mission on that directory. Because the execute permission on a directory is crucial for user access, it is commonly given to all users via the other category, unless the directory must be private.

Error creating thumbnail: Unable to save thumbnail to destination

userpermission