These are examples of the results after running the rb_who.d script.

This script shows which UIDs and PIDs are running Ruby programs with Ruby
provider support, and how active they are.  It lists the name of the program,
along with the number of lines executed per program as recorded by the line
provider.

Here it runs as three Ruby programs are executed.  Code/Ruby/func_abc.rb runs
twice and Code/Ruby/func_slow.rb once.

# rb_who.d
Tracing... Hit Ctrl-C to end.
^C
      PID    UID      LINES FILE
   146485      0         12 ./func_abc.rb
   146486      0         12 ./func_abc.rb
   146487      0    1200015 ./func_slow.rb

You can see that func_abc.rb has twelve lines of executable Ruby code, and
that func_slow.rb has 100,000x that.