Demonstrate templating with Makefile target and /bin/echo

Makefile

#****************************************************************************
#
#    GNU/       __  __       _         __ _ _      
#      /gmake  |  \/  | __ _| | _____ / _(_) | ___ 
#     /        | |\/| |/ _` | |/ / _ \ |_| | |/ _ \
#    /BSD-2c   | |  | | (_| |   <  __/  _| | |  __/
#              |_|  |_|\__,_|_|\_\___|_| |_|_|\___|
#
#                           HEREDOC
#
#   FILENAME: Makefile  AUTHOR: "Brig Young" 
#   COPYRIGHT: "2016 Brig Young" LICENSE: "BSD-2c"
#   PURPOSE: Deomonstrate templating with Makefile target and /bin/echo
#
#                This file probably requires GNU gmake.
#****************************************************************************
MAKE_VARIABLE = --std=c11 --pedantic -fpcc-struct-return
OUTPUT_DIR = .
OUTPUT_FILENAME = heredoc.output

heredoc:
        @/bin/echo -e \
This is some text followed by a newline\\n\
and this is an interpolated make variable: $(MAKE_VARIABLE).\\n\
and this is not: MAKE_VARIABLE.\\n\
See man echo for details. >> $(OUTPUT_DIR)/$(OUTPUT_FILENAME)

clean:
        rm heredoc.output

test.output

brig@something ~/src/makefile_HEREDOC $ ls
Makefile
brig@something ~/src/makefile_HEREDOC $ make
brig@something ~/src/makefile_HEREDOC $ ls
heredoc.output  Makefile
brig@something ~/src/makefile_HEREDOC $ cat heredoc.output 
This is some text followed by a newline
and this is an interpolated make variable: --std=c11 --pedantic -fpcc-struct-return.
and this is not: MAKE_VARIABLE.
See man echo for details.
brig@something ~/src/makefile_HEREDOC $ make clean
rm heredoc.output
brig@something ~/src/makefile_HEREDOC $ ls
Makefile
brig@something ~/src/makefile_HEREDOC $