return distro name in a lower string

getdistro.bash

# return distro name in a lower string

function getdistro()
{   
    _distro_var_DIST_INFO="/etc/lsb-release"
    if [ -r "$_distro_var_DIST_INFO" ]; then
        . "$_distro_var_DIST_INFO"
    fi

    if [ -z "$DISTRIB_ID" ]; then
        _distro_var_DISTRIB_ID="Unknown";
        if [ -f /etc/arch-release ]; then
            _distro_var_DISTRIB_ID="Arch"
        elif [ -r /etc/knoppix-version ]; then
            _distro_var_DISTRIB_ID="Knoppix"
        elif [ -r /etc/sidux-version ]; then
            _distro_var_DISTRIB_ID="Sidux"
        elif [ -r /etc/debian_version ]; then
            _distro_var_DISTRIB_ID="Debian"
        elif [ -r /etc/issue ]; then
            _distro_var_DISTRIB_ID=$(cat /etc/issue.net | awk '{print $1}')
            if [ X"$_distro_var_DISTRIB_ID" = X"Ubuntu" ]; then
                _distro_var_DISTRIB_ID=Ubuntu
            fi
        elif [ -r /etc/gentoo-release ]; then
            _distro_var_DISTRIB_ID="Gentoo"
        elif [ -f /etc/lfs-version ]; then
            _distro_var_DISTRIB_ID="LFS"
        elif [ -r /etc/pclinuxos-release ]; then
            _distro_var_DISTRIB_ID="PCLinuxOS"
        elif [ -f /etc/mandriva-release ] || [ -f /etc/mandrake-release ]; then
            _distro_var_DISTRIB_ID="Mandriva"
        elif [ -f /etc/redhat-release ]; then
            _distro_var_DISTRIB_ID="RedHat"
        elif [ -f /etc/fedora-release ]; then
            _distro_var_DISTRIB_ID="Fedora"
        elif [ -r /etc/vector-version ]; then
            _distro_var_DISTRIB_ID="VectorLinux"
        elif [ -r /etc/slackware-version ]; then
            _distro_var_DISTRIB_ID="$(cat /etc/slackware-version)"
        elif [ -f /etc/release ]; then
            _distro_var_DISTRIB_ID="Solaris"
        elif [ -r /etc/SuSE-release ]; then
            _distro_var_DISTRIB_ID="$(grep -i suse /etc/SuSE-release)"
        elif [ -f /etc/yellowdog-release ]; then
            _distro_var_DISTRIB_ID="YellowDog Linux"
        elif [ -f /etc/zenwalk-version  ]; then
            _distro_var_DISTRIB_ID="Zenwalk"
        fi
        printf "%s\\n" "$_distro_var_DISTRIB_ID" | tr 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' 'abcdefghijklmnopqrstuvwxyz'
    else
        printf "%s\\n" "$DISTRIB_ID" | tr 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' 'abcdefghijklmnopqrstuvwxyz'
    fi
}