x=$'\\a\\b\\c\\\001\\d\\e\\f'
y='\a\b\c\
\d\e\f'
z=$'abc\001def'

recho "$x"
recho "$y"
recho "$z"

case $'abc\001def' in
$x) echo ok 1 ;;
*) echo oops 1;;
esac

case $z in
$x) echo ok 2 ;;
*) echo oops 2;;
esac

case $'abc\001def' in
$y) echo ok 3 ;;
*) echo oops 3;;
esac

case $z in
$y) echo ok 4 ;;
*) echo oops 4;;
esac

# no backslash before \001
x=$'\\a\\b\\c\001\\d\\e\\f'
y='\a\b\c
\d\e\f'

case $'abc\001def' in
$x) echo ok 5 ;;
*) echo oops 5;;
esac

case $z in
$x) echo ok 6 ;;
*) echo oops 6;;
esac

case $'abc\001def' in
$y) echo ok 7 ;;
*) echo oops 7;;
esac

case $z in
$y) echo ok 8 ;;
*) echo oops 8;;
esac