/etc/lsb-release 

DISTRIB_ID=Kali
DISTRIB_RELEASE=2.0
DISTRIB_CODENAME=sana
DISTRIB_DESCRIPTION="Kali GNU/Linux 2.0"

/usr/lib/os-release

PRETTY_NAME="Kali GNU/Linux 2.0 (sana)"
NAME="Kali GNU/Linux"
ID=kali
VERSION="2.0 (sana)"
VERSION_ID="2.0"
ID_LIKE=debian
ANSI_COLOR="1;31"
HOME_URL="kali.org/"
SUPPORT_URL="forums.kali.org/"
BUG_REPORT_URL="bugs.kali.org/"