This is an example of using a Here document (Heredoc) in bash to write an inline string to a file.
cat <<EOF >/etc/dhcp/dhcpd.conf authoritative; default-lease-time 86400; max-lease-time 86400; subnet 192.168.99.0 netmask 255.255.255.0 { range 192.168.99.100 192.168.99.150; option routers 192.168.99.1; option domain-name-servers 192.168.99.1; option domain-name "local"; } EOF