>> How does a program in Gentoo know, where to look for shared libraries? > > The program doesn't know. But the runtime linker does. And those paths are > in /etc/ld.so.conf. This file gets updated automatically by portage when > needed. > > But... sometimes the program also knows and can link against libraries long > after it has started up using a dlopen() call: > > http://linux.die.net/man/3/dlopen >
Thank you Nikos. I did read obout this in the Linux HOWTO: http://www.faqs.org/docs/Linux-HOWTO/Program-Library-HOWTO.html#DL-LIBRARIES But I was woundering if the /etc/ld.so.conf was only historical stuff. O.K. is not it's up-to-date. Good to know this. But it also writes that dlopen() is specific for Linux and Solaris. There would be alternatives: 1.) The glib library 2.) libltdl, which is part of GNU libtool Now I was woundering, which way would Gentoo choose or if that is not package specific at all. Are you sure dlopen() is used as a general approach on Gentoo? Also I installed a few libries with Prefix Gentoo on Cygwin. On Cygwin there is no /etc/ld.so.conf. Yet the libraries are found somehow. I still have to find out how it works in that environment. Al