A+ - like 'cat -A' with Unicode symbols

aplus.sh

#!/bin/bash
# h/t: https://unix.stackexchange.com/a/196783/278323
#
# Unicode characters
# ⇥  (rightwards arrow to bar)
#    https://www.fileformat.info/info/unicode/char/21e5/index.htm
#
# ·  (middle dot)
#    https://www.fileformat.info/info/unicode/char/00b7/index.htm
#
# ↲  (downwards arrow with tip leftwards)
#    https://www.fileformat.info/info/unicode/char/21b2/index.htm
#      
# ␣  (open box)
#    https://www.fileformat.info/info/unicode/char/2423/index.htm

TAB=$(echo -e '\u21e5   ')
NL=$(echo -e '\u21b2')
SPACE=$(echo -e '\u00b7')
# uncomment this to use open box instead of middle dot
#SPACE=$(echo -e '\u2423')

sed "s/ /$SPACE/g; s/\t/$TAB/g; s/\(.*\)$/\1$NL/" ${1:+"$@"}