Peter's Site - Programs

Shared libs in /usr/local/lib

nospam@example.com (Peter) — Wed, 24 Sep 2008 12:23:58 +0200

Just a quick note to myself:
In Linux, shared C object libraries (.so) are usually found in /usr/lib which is also in the default linker search path. A problem arises when compiling programs requiring shared libraries located in /usr/local/lib, the directory for non-system libraries. The resulting binary can usually not be executed, since the shared object files are not found during runtime. Common hacks are setting the LD_LIBRARY_PATH environment variable (linker search path) to include /usr/local/lib or editing /ect/ld.so.conf to include this path.

A more portable solution is to include /usr/local/lib in the run path of the binary file with the ld option -R. When using g++ for linking, use the option -Wl,-rpath,/usr/local/lib. The resulting binary can now run without extra hacks.

More info.

Validation Graphs

nospam@example.com (Peter) — Tue, 13 Jun 2006 20:50:12 +0200

After having a some fun with the Page Graphs, I eventually made an old dream of mine reality: Builing a small program which does link checking and page validation while spidering a website. Combined with the particle graph visualization method, it is a great tool to get a quick overview of a website's structure and validation status.
Look here for more

Page Graphs GUI

nospam@example.com (Peter) — Thu, 01 Jun 2006 18:20:36 +0200

I put my little PageGraphGUI application including sources online.
Have fun with it.
Look here for more..

Particle Graphs

nospam@example.com (Peter) — Wed, 31 May 2006 20:08:09 +0200

After stumbling across the websites as graphs blog entry at aharef.info, I was fascinated by the simplicity and beauty of this visualization algorithm.
Immediatly I took the code of the underlying Java applet and built a small Swing GUI which embeds this particle engine. The frame is resizable and images can be saved.
I will make the sources available in some days, after fixing some bugs. Eventually I will spend more time in it, because the underlying potential is big. One can think of visualizing arbitrary XML structures or other tree-like information. I also started using it for visualization of link structures in web sites.