$echo $BASH

$BASH                 $BASH_COMPLETION      $BASH_SUBSHELL
$BASH_ARGC            $BASH_COMPLETION_DIR  $BASH_VERSINFO
$BASH_ARGV            $BASH_LINENO          $BASH_VERSION
$BASH_COMMAND         $BASH_SOURCE

$echo $

$_                     $GROUPS                $OSTYPE
$BASH                  $HISTCMD               $PATH
$bash205               $HISTCONTROL           $PIPESTATUS
$bash205b              $HISTFILE              $PPID
$bash3                 $HISTFILESIZE          $PROMPT_COMMAND
$BASH_ARGC             $HISTSIZE              $PS1
$BASH_ARGV             $HOME                  $PS2
$BASH_COMMAND          $HOSTNAME              $PS4
$BASH_COMPLETION       $HOSTTYPE              $PWD
$BASH_COMPLETION_DIR   $IFS                   $RANDOM
$BASH_LINENO           $L3_HOME               $SECONDS
$BASH_SOURCE           $L3_PARENT_TTY         $SHELL
$BASH_SUBSHELL         $L3_SESSION_ID         $SHELLOPTS
$BASH_VERSINFO         $L3_TAMPERED_EDITORS   $SHLVL
$BASH_VERSION          $LANG                  $SSH_AGENT_PID
$COLUMNS               $LESSCLOSE             $SSH_AUTH_SOCK
$COMP_WORDBREAKS       $LESSOPEN              $TERM
$DESKTOP_SESSION       $LINENO                $TIME
$DIFFNAME              $LINES                 $UID
$DIR                   $LOGNAME               $USER
$DIRSTACK              $LS_COLORS             $USERNAME
$DISPLAY               $MACHTYPE              $WINDOWID
$editor_file           $MAILCHECK             $XAUTHORITY