#!/bin/bash
# here-commsub.sh
# Requires Bash version -ge 4.1 ...

multi_line_var=$( cat <<ENDxxx
------------------------------
This is line 1 of the variable
This is line 2 of the variable
This is line 3 of the variable
------------------------------
ENDxxx)

#  Rather than what Bash 4.0 requires:
#+ that the terminating limit string and
#+ the terminating close-parenthesis be on separate lines.

# ENDxxx
# )


echo "$multi_line_var"

#  Bash still emits a warning, though.
#  warning: here-document at line 10 delimited
#+ by end-of-file (wanted `ENDxxx')