How does “cat << EOF” work in bash?

Question

I needed to write a script to enter multi-line input to a program (psql).

After a bit of googling, I found the following syntax works:

c         


        

Answer 1

This isn't necessarily an answer to the original question, but a sharing of some results from my own testing. This:

< print.sh
#!/bin/bash
echo \$PWD
echo $PWD
test

will produce the same file as:

cat < print.sh
#!/bin/bash
echo \$PWD
echo $PWD
test

So, I don't see the point of using the cat command.