upgrade.script

buildBinary(){
    curl -s https://raw.githubusercontent.com/Sid-Sun/codeMKII/master/codeMK2.c > /tmp/codeMK2.c
    cd /tmp/
    read -r -p "Which compiler do you want to use? [gcc/clang] " response
    if [[ "$response" =~ ^([gG][cC][cC]|[gG])+$ ]]
    then
        gcc -o codeMK2 codeMK2.c
    else
        clang -o codeMK2 codeMK2.c
    fi
}
replaceBinary(){
    export savedGroup=$(ls -l $pathToBinary | awk '{print $4}') #save group so we can chown later on and apply the previous group, do it before check as we need to store it on either cases
    export savedPermissions=$(stat -c "%a %n" $pathToBinary | awk '{print $1}'); #Save file permissions too; in case user uses something other than 755.
    if [[ $(ls -l $pathToBinary | awk '{print $3}') == $USER ]] #Check if current user owns the binary 
    then
        mv /tmp/codeMK2 $pathToBinary
        chmod $savedPermissions $pathToBinary
        if [[ $USER != $savedGroup ]]
        then
            chown :$savedGroup $pathToBinary
        fi
        echo "Upgrade completed."
    else
        read -r -p "The binary file is not owned by "$USER", do you wish to try with superuser privileges? (y/n): " response
        if [[ "$response" =~ ^([yY][eE][sS]|[yY])+$ ]]
        then
            sudo mv /tmp/codeMK2 $pathToBinary
            sudo chmod $savedPermissions $pathToBinary
            sudo chown :$savedGroup $pathToBinary
            echo "Upgrade completed successfully if the superuser privileges were granted."
        else
            echo "Upgrade aborted."
        fi
    fi
    rm -f /tmp/codeMK2.c #Remove the curl'd source regardless of the upgrade succeeding.
}
readlinkRecursively(){
    toCheck=$1
	export checkedWithReadlink=$(readlink $toCheck | awk '{print $1}');
    if [[ $checkedWithReadlink != '' ]]
    then
        readlinkRecursively "$checkedWithReadlink"
     fi
}
export upstreamVersion=$(curl -s https://raw.githubusercontent.com/Sid-Sun/codeMKII/master/version.number | cat)
if [[ $currentlyInstalledVersion != $upstreamVersion ]]
then
    read -r -p "Update to "$upstreamVersion" is available, installed version is "$currentlyInstalledVersion" do you want to upgrade now? (y/n): " response
    if [[ "$response" =~ ^([yY][eE][sS]|[yY])+$ ]]
    then
        export checkAliased=$(type $calledCommand | awk '{print $3}')
        if [[ $checkAliased == "aliased" ]]
        then
            readlinkRecursively $(type $calledCommand | awk '{print $5}')
            export pathToBinary=$toCheck
            buildBinary
            replaceBinary
        else
            readlinkRecursively $checkAliased
            export pathToBinary=$toCheck
            buildBinary
            replaceBinary
        fi
    else
        echo "Okay, Just run "$calledCommand" with -u argment again whenever you wish to upgrade."
    fi
else
    echo "You are running the latest version, "$currentlyInstalledVersion
fi
exit