I have developed software tools and scripts in different programming language since 1997. I mainly used C (sometimes bash, csh, etc.) under Unix/Linux before 2010, but moved to python (sometimes PHP/SQL under Linux/MySQL) after 2010. The code examples below are Python (upsvr1.8.py), PHP/SQL (weberp-operate-db-meta.php) and Bash (ip2xx2ecmsbackup2excludelist20120224.sh) codes developed during 2011-2014 and C (kdtree.c) codes developed in 2006.

My recent code samples can be found at my github site (https://github.com/xiezhq/isescan) where ISEScan is a pipeline I developed to automatically identify mobile genetic elements in bacterial genome and metagenome. I mainly used C to develop the CPU-intensive applications in structural bioinformatics, specifically, protein structure and modeling. 

You can also find some obsolete but still usable C code examples at https://github.com/xiezhq/builddata, which is used to analyze the protein-protein interface in protein complex.