Difference of EOF

（1） Use cat <<EOF when , When we're done typing , On the last line, enter EOF As an end sign , At the same time, the last line EOF Must top grid ,EOF You can't use tabs or spaces in the front , Otherwise, an error will be reported when executing the script , Because the end resolver EOF It's preceded by tabs or spaces , be EOF It's not going to be used as a closing line , Will only continue to be treated as stdin To input .
(1.1) The last line EOF Vertex lattice , Perform normally


（1.2） The last line ,EOF Not top grid , Report errors

（2） Use cat <<-EOF when , When we're done typing , On the last line, enter EOF As an end sign , At the same time, the last line EOF unlimited ,EOF You can use tabs in front
（2.1）EOF Vertex lattice , Perform normally


（2.2）EOF front +tab, The execution is also normal