source: vendor/bash/3.1/tests/nquote.tests

expect()
{
        echo expect "$@"
}

expect '<^J^J^J>'
recho $'\n\n\n'

expect '<++^J++>'
f=$'\n'
recho "++$f++"
unset f

z1=$''
expect '<>'
recho "$z1"

ZIFS=$'\n'$'\t'$' '

expect '<^J^I >'
recho "$ZIFS"

expect '<abc>'
recho $'abc'

expect '<^M^[^Gabc>'
recho $'\r\e\aabc'

D=$"hello"," "$"world"

expect '<hello,> <world>'
recho $D

expect '<hello, world>'
recho "$D"

D=$""
expect '<>'
recho "$D"

world=chet

expect '<$hello, world>'
recho \$"hello, world"

expect '<hello, $world>'
recho $"hello, \$world"

expect '<hello, "world">'
recho $"hello, \"world\""

expect '<hello, $"world">'
recho $"hello"', $"world"'

expect '<hello, $"world">'
recho $'hello, $"world"'

expect '<$hello, chet>'
recho \$"hello, $world"

expect '<hello, chet>'
recho $"hello, $world"

z=$'\v\f\a\b'
case "$z" in
$'\v\f\a\b')    echo ok;;
*)              echo bad;;
esac

# Dave Korn says this should be allowed and echo 'abcd'
echo $'\'abcd\''

# printf translates \' to ' ...
printf "\'abcd\'\n"

# but echo -e doesn't
echo -e "\'abcd\'"
echo -e "\\'abcd\\'"

# and what do we do about unrecognized escape sequences?

shopt -s xpg_echo

recho $'A\CB'

recho "A\CB"

cde=c
recho $'ab$cde'

printf "%b\n" 'A\CB'
printf 'A\CB\n'

echo 'A\CB'

world=chet

recho $'hello, $"world"'
recho $'hello, \$"world"'
recho $'hello, $\"world"'

recho "hello, $"world""