so file 생성

http://blog.jeffscudder.com/2008/04/creating-and-using-so-files-with-gcc.html

http://www.experts-exchange.com/OS/Linux/Distributions/Q_24069408.html

export LD_LIBRARY_PATH=`pwd`

gcc -c -fpic speciallib.c

gcc -shared -lc -o speciallib.so speciallib.o

gcc main.c -ldl