1task :default => :build
 2
 3task :clean do
 4  sh 'rm -f *.so'
 5end
 6
 7desc 'build libgreeting.so'
 8task :build => :clean do
 9  sh 'gcc -shared -o libgreeting.so -fPIC greeting.c'
10end
11
12desc 'run the example'
13task :run => :build do
14  sh 'LD_LIBRARY_PATH=. ruby greeting.rb'
15end