gksudo gedit

~/ > whoami
paul
~/ > sudo whoami
root
~/ > id
uid=1000(paul) gid=1000(paul) groups=1000(devs),4(adm),20(dialout),24(cdrom),…
~/ > sudo id
uid=0(root) gid=0(root) group=0(root)

lsattr /etc/dhcp/dhcpd.config

chattr -i /etc/dhcp/dhcpd.config

su
<texteditor> /etc/dhcp/dhcpd.config

ls  -al

sudo mv example.txt /etc/dhcp/

sudo chmod -R your-user-name:admin .

sudo < editor > < filelocation >

admin:///etc/default/grub