How do you compare versions in InstallScript?

Question

It looks like there is a builtin function, VerCompare, but it requires strings that have all four components, e.g. 1.2.3.4. I haven't tried to do string manipulation in InstallScript and was hoping someone already had the code to take a version string and add .0's as necessary.

Answer 1

Needs some error checking, but here's the general idea:

prototype NUMBER CompareVersions(STRING, STRING);
prototype STRING FormatVersion(STRING);

function NUMBER CompareVersions(leftVersion, rightVersion)
    STRING formattedLeftVersion, formattedRightVersion;
begin
    formattedLeftVersion = FormatVersion(leftVersion);
    formattedRightVersion = FormatVersion(rightVersion);

    return VerCompare(formattedLeftVersion, formattedRightVersion, VERSION);
end;

function STRING FormatVersion(version)
    STRING formattedVersion;
    LIST tokens;
    NUMBER count;
begin
    tokens = ListCreate(STRINGLIST);
    StrGetTokens(tokens, version, ".");
    count = ListCount(tokens);
    ListSetIndex(tokens, LISTLAST);
    while (count < 4)
        ListAddString(tokens, "0", AFTER);
        count = count + 1;
    endwhile;
    StrPutTokens(tokens, formattedVersion, ".", FALSE);
    ListDestroy(tokens);
    return formattedVersion;
 end;