[ -n "$VERCOMP_HELPER" ] && return || readonly VERCOMP_HELPER=1

vercomp_internal () {
    if [[ $1 == $2 ]]
    then
        return 0
    fi
    local IFS=.
    local i ver1=($1) ver2=($2)
    # fill empty fields in ver1 with zeros
    for ((i=${#ver1[@]}; i<${#ver2[@]}; i++))
    do
        ver1[i]=0
    done
    for ((i=0; i<${#ver1[@]}; i++))
    do
        if [[ -z ${ver2[i]} ]]
        then
            # fill empty fields in ver2 with zeros
            ver2[i]=0
        fi
        if ((10#${ver1[i]} > 10#${ver2[i]}))
        then
            return 1
        fi
        if ((10#${ver1[i]} < 10#${ver2[i]}))
        then
            return 2
        fi
    done
    return 0
}

vercomp() {
    vercomp_internal $1 $2
    case $? in
        0) op='=';;
        1) op='>';;
        2) op='<';;
    esac

    echo "$op"
}
## vim: set ft=sh sw=4 sts=4 et foldmethod=syntax : ##