$ /bin/sh -c 'echo $SHELL'
/bin/bash

##</code><code>##

$ file /bin/sh
/bin/sh: symbolic link to `dash'

##</code><code>##

$ file /bin/dash
/bin/dash: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.26, BuildID[sha1]=0x890a514bd261794a6d39da58ea2372fdf48e98d6, stripped