$ env -i bash --noprofile --norc
$ export
declare -x OLDPWD
declare -x PWD="/home/t"
declare -x SHLVL="1"

$ env -i bash --noprofile --norc
$ set
BASH=/bin/bash
BASHOPTS=cmdhist:complete_fullquote:expand_aliases:extquote:force_fignore:hostcomplete:interactive_comments:progcomp:promptvars:sourcepath
BASH_ALIASES=()
BASH_ARGC=()
BASH_ARGV=()
BASH_CMDS=()
BASH_LINENO=()
BASH_SOURCE=()
BASH_VERSINFO=([0]="4" [1]="3" [2]="48" [3]="1" [4]="release" [5]="x86_64-pc-linux-gnu")
BASH_VERSION='4.3.48(1)-release'
COLUMNS=80
DIRSTACK=()
EUID=1000
GROUPS=()
HISTFILE=/home/user/.bash_history
HISTFILESIZE=500
HISTSIZE=500
HOSTNAME=a
HOSTTYPE=x86_64
IFS=$' tn'
LINES=24
MACHTYPE=x86_64-pc-linux-gnu
MAILCHECK=60
OPTERR=1
OPTIND=1
OSTYPE=linux-gnu
PATH=/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin:.
PPID=30961
PS1='s-v$ '
PS2='> '
PS4='+ '
PWD=/home/user
SHELL=/bin/bash
SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
SHLVL=1
TERM=dumb
UID=1000
_=bash