[fpc-pascal] HMAC_SHA1 and FPC

[Marcos Douglas]

On Tue, Mar 26, 2013 at 10:05 AM, Anthony Walter <sysrpl at gmail.com> wrote:
> On Tue, Mar 26, 2013 at 5:57 AM, Marcos Douglas <md at delfire.net> wrote:
>>
>> Hi,
>> Is possible to make that only using Windows for any lib?
>>
>> Best regards,
>> Marcos Douglas
>
>
> Marcos,
>
> Are you asking, "Is it possible to build any static lib for Windows and link
> it to a free pascal project"?

Yes, that's it. Thank you.

> No, not all the time. Libraries may depend on systems function on one
> platform which are not available on another.
>
> But, many times you can if the library can compile with mingw64. When this
> is the case you build a C project using mingw64, copy the lib files to a
> directory free pascal is using (see environment settings in lazarus), list
> the functions in a unit, then put {$linklib youlibname.a} in the
> implementation section. You may need a few {$ifdef}s for your different
> platforms.

I had seen this $linklib but I did not know what it was for.

> The benefit of this is that you can easily incorporate (much more easily
> rewriting) *complex* functionality into your free pascal projects knowing
> what you are reusing is probably faster, has more features, is more robust,
> and better tested than a implementation of X that someone reinvented again
> for free pascal.
>
> Sometimes though you might be are better off using dynamic linking (so, dll
> on windows) if you know the OS is going to provide features. Examples are
> msxml.dll vs libxml2.so, gdiplus.dll vs libcario.so, ect. Of course in these
> cases what probably you need to do is write some lite wrappers, since the
> apis vary in form (but not function). In those cases I typically use
> interfaces...
>
> IXmlDocument, IXmlNode // for pasring or building Xml
> ICanvas, IBrush // for drawing
>
> and then
>
> function CreateXmlDocument: IXmlDocument; {$fidef}s
> function CreateCanvas: ICanvas; {$fidef}s

Good ideas. Thank you for share.

Marcos Douglas