dbx adds the following features as extensions:
$[ p– > flags ] language expression
typeset -q enables special quoting for user-defined functions
C shell-like history and alias arguments
set +o path disables path searching
0xabcd C syntax for octal and hexadecimal numbers
bind to change Emacs-mode bindings
set -o hashall
set -o ignore suspend
print -e and read -e (opposite of -r, raw)
Built-in dbx commands