What do you do when a friend wants to send you some special digital xmas present? Setup a ftp server or use your existing ssh infrastructure to create a secure connection between both? I decided to do the latter one because last time I did it was only an emerge scponly which created everything for me.

@Zoby, this time it is my program you should try to analyse. It isn't that hard but I hope you have some fun with it. As small hint: it is related to a mathematician who participated in an infamous project.

While fixing linking problems of libg3d on windows I checked the binutils ld man page again after years and noticed that there are some useful parameter to check for linking misbehaviour on linux. In some rare situations it is a design decision of upstream and not a really "bug" but in most cases someone forgot to link against a library and his current system configuration hides the problem from him. So it isn't a good idea to insist on a bug in upstream or "fixing" it without listening to upstream - unless you liked the the infamous openssl random number genererator bug in debian related distributions.

OpenSSH has some really nice unknown options which you find from time to time per accident. One of them is to share a connection between different sessions. It helps a lot when you are using multiple connections to a host or using zsh autocompletion over ssh and must wait until the connection was really established.