version.sh

#!/usr/bin/env bash
version_compare () {
    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
}

test_version_compare () {
    vercomp ${1:-} ${2:-}
    case $? in
        0) op='=';;
        1) op='>';;
        2) op='<';;
    esac
    if [[ $op != ${3:-} ]]
    then
        echo "FAIL: Expected '${3:-}', Actual '$op', Arg1 '${1:-}', Arg2 '${2:-}'"
    else
        echo "Pass: '${1:-} $op ${2:-}'"
    fi
}