update:
I have installed zlib-1.2.5 (without problems) and also openssl-1.0.0. This last gave me a couple of errors, but eventually I managed to install it with no final warning... but stil rtmpdump won't compile.. any suggestion?
At this point I even consider the possibility to download another software/command line software. Sometimes you have juts have to give up and face your limits
(I refer to myself
)