This is a list of examples of the usage of rb_funccalls.d. It reports method calls from all Ruby programs on the system that are running with Ruby provider support. Here we run it while the program Code/Ruby/func_abc.rb is executing. # rb_funccalls.d Tracing... Hit Ctrl-C to end. ^C FILE CLASS METHOD CALLS func_abc.rb Object func_a 1 func_abc.rb Object func_b 1 func_abc.rb Object func_c 1 func_abc.rb IO write 3 func_abc.rb Module method_added 3 func_abc.rb Object print 3 func_abc.rb Object sleep 3 We can see that during that one Ruby program, Our 3 user-defined methods, func_a, func_b and func_c are called once each. Amongst other calls we can see that a method from class IO - write, was called three times; probably by the print method. If you look at the example program Code/Ruby/func_abc.rb, you can see that 'print' is used three times, but IO::write is never directly called.