Windows and Linux Real time scenarios and answers that Works

How to restore default system permissions on Red Hat, CentOs, Fedora I recently came across a system which had some directories set to 777(recursively), the sysadmin needed to install an application and changed all the permissions!!!! a mess, I didn't know where to start, but one of my colleagues pointed that rpm has a parameter called --setperms and --setugids. I created a one liner that does the job, it takes time but It works !!!!! 1) To reset uids and gids on files and directories : for u in $(rpm -qa); do rpm --setugids $u; done 2) To permissions on files and directories for p in $(rpm -qa); do rpm --setperms $p; done # ll /etc/ssh/ # chmod 600 /etc/ssh/ssh_host_rsa_key # chmod 600 /etc/ssh/ssh_host_dsa_key # service sshd restart