CleanChat-AutoClearChannel AutoUpdate script

#!/usr/bin/env bash

#SETTINGS

DLL="CleanChat-AutoClearChannel.dll"
VERSION_URL="http://drive.alexandernorup.com/CleanChat/latest.txt"
DOWNLOAD_URL="http://drive.alexandernorup.com/CleanChat/latest.zip"


#Thanks to "Paused until further notice." on Stackoverflow <3
#https://stackoverflow.com/a/4025065
vercomp () {
    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
}

testvercomp () {
    vercomp $1 $2
    case $? in
        0) op='=';;
        1) op='>';;
        2) op='<';;
    esac
    if [[ $op != $3 ]]
    then
        echo "Server is up to date!"
        start_server
        return 0
    else
        do_update $2
    fi
}

get_version() {
   strings $DLL | egrep '^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$'
}

get_latest_version() {
   curl -s --user-agent "CleanChat Auto Updater" $VERSION_URL
}

do_update () {
   echo "New update ready to download: v. $1"
   curl -o "update.zip" --user-agent "CleanChat AutoUpdater" $DOWNLOAD_URL
   echo "Update downloaded!"
   unzip -o "update.zip"
   rm "update.zip"
   echo "Update installed!"
   start_server
}

start_server () {
   echo "Starting server..."
   dotnet $DLL
}

VERSION=$(get_version)
NEWEST=$(get_latest_version)
echo "Checking for updates..."
echo "Current version: $VERSION"
echo "Newest version: $NEWEST"
testvercomp $VERSION $NEWEST '<'