# I fell in love with this: https://stackoverflow.com/questions/9274205/rake-watch-for-changes file 'main.o' => ["main.c", "greet.h"] do sh "cc -c -o main.o main.c" end file 'greet.o' => ['greet.c'] do sh "cc -c -o greet.o greet.c" end file "hello" => ["main.o", "greet.o"] do sh "cc -o hello main.o greet.o" end