distro

#!/bin/bash
#
# This script determines the Linux distribution we are running
# on. It output two words: (1) The distro name and (2) the version
# Example output "UBUNTU 10.04"

# Ubuntu is detected with /etc/lsb-release
SEP=${1:- }
if [ -e /etc/lsb-release ]
then
    . /etc/lsb-release
    if [ -n "$DISTRIB_ID" -a -n "$DISTRIB_RELEASE" ] ; then
        echo "${DISTRIB_ID^^*}$SEP$DISTRIB_RELEASE"
        exit 0
    fi
fi

# Debian
if [ -e /etc/debian_version ]; then
    VERSION=`cat /etc/debian_version`
    VERSION=${VERSION%%.*}
    if [ $VERSION = 'wheezy/sid'   ]; then VERSION="7";  fi
    if [ $VERSION = 'jessie/sid'   ]; then VERSION="8";  fi
    if [ $VERSION = 'stretch/sid'  ]; then VERSION="9";  fi
    if [ $VERSION = 'buster/sid'   ]; then VERSION="10"; fi
    if [ $VERSION = 'bullseye/sid' ]; then VERSION="11"; fi
    if [ $VERSION = 'bookworm/sid' ]; then VERSION="12"; fi
    echo "DEBIAN$SEP$VERSION"
    exit 0
fi

# RedHat / CentOS
if [ -e /etc/redhat-release ]
then
    # CentOS release 5.4 (Final)
    VERSION=$(cat /etc/redhat-release)
    if [ "${VERSION:0:6}" = CentOS ]
    then
        if [ "${VERSION:0:24}" = "CentOS Linux release 6.0" ]; then
            echo "CENTOS${SEP}6"
            exit 0
        elif [ "${VERSION:0:22}" = "CentOS Linux release 7" ]; then
            echo "CENTOS${SEP}7"
            exit 0
        elif [ "${VERSION:0:22}" = "CentOS Linux release 8" ]; then
            echo "CENTOS${SEP}8"
            exit 0
        fi
        echo "CENTOS$SEP${VERSION:15:1}"
        exit 0
    elif [ "${VERSION:0:24}" = "Red Hat Enterprise Linux" ]
    then
        echo "REDHAT$SEP${VERSION:40:1}"
        exit 0
    elif [ "${VERSION:0:6}" = "Fedora" ]
    then
        [[ $VERSION =~ (Fedora release ([0-9]+)) ]] && REL=${BASH_REMATCH[2]} || exit 0
        echo "FEDORA$SEP$REL"
        exit 0
    elif [ "${VERSION:0:5}" = "Rocky" ]
    then
        [[ $VERSION =~ (Rocky Linux release ([0-9]+)) ]] && REL=${BASH_REMATCH[2]} || exit 0
        echo "ROCKY$SEP$REL"
        exit 0
    fi
fi

# SLES
if [ -e /etc/SuSE-release ]
then
    # SLES 11
    VERSION=$(sed -rn 's/^VERSION = (.*)/\1/p' < /etc/SuSE-release)
    SP=$(sed -rn 's/^PATCHLEVEL = (.*)/\1/p' < /etc/SuSE-release)
    if [ "$VERSION" = 11 -a "$SP" = 1 ] 
    then
        echo "SLES$SEP${VERSION}SP1"
        exit 0
    elif [ "$VERSION" = 11 -a "$SP" = 2 ] 
    then
        echo "SLES$SEP${VERSION}SP2"
        exit 0
    elif [ "$VERSION" = 11 -a "$SP" = 3 ] 
    then
        echo "SLES$SEP${VERSION}SP3"
        exit 0
    elif [ "$VERSION" = 11 -a "$SP" = 4 ]
    then
        echo "SLES$SEP${VERSION}SP4"
        exit 0
    elif [ "$VERSION" = 10 -a "$SP" = 1 ] 
    then
        echo "SLES$SEP${VERSION}SP1"
        exit 0
    elif [ "$VERSION" = 10 -a "$SP" = 2 ] 
    then
        echo "SLES$SEP${VERSION}SP2"
        exit 0
    elif [ "$VERSION" = 11 ]
    then
        echo "SLES$SEP${VERSION}"
        exit 0
    elif [ "$VERSION" = 12 ]
    then
        echo -n "SLES$SEP${VERSION}"
        if [ $SP != 0 ]; then
            echo "SP$SP"
        else
            echo
        fi
        exit 0
    elif [ "$VERSION" = 12.1 ]
    then
        echo "OPENSUSE$SEP${VERSION}"
        exit 0
    fi
fi

# SLES > 15
if [ -e /etc/os-release ]
then
    NAME=$(sed -rn 's/^NAME="(.*)"/\1/p' < /etc/os-release)
    if [ "$NAME" = "SLES" ]; then
        VERSION=$(sed -rn 's/^VERSION="(.*)"/\1/p' < /etc/os-release)
        echo "$NAME$SEP${VERSION/-/}"
        exit 0
    fi
    if [ "$NAME" = "openSUSE Leap" ]; then
        NAME="OPENSUSE"
        VERSION=$(sed -rn 's/^VERSION="(.*)"/\1/p' < /etc/os-release)
        echo "$NAME$SEP${VERSION}"
        exit 0
    fi
fi

exit 1