set_trace_func

set_trace_func(proc) â proc
set_trace_func(nil) â nil

Instance Public methods

Establishes proc as the handler for tracing, or disables tracing if the parameter is nil.

proc takes up to six parameters:

an event name
a filename
a line number
an object id
a binding
the name of a class

proc is invoked whenever an event occurs.

Events are:

c-call: call a C-language routine
c-return: return from a C-language routine
call: call a Ruby method
class: start a class or module definition),
end: finish a class or module definition),
line: execute code on a new line
raise: raise an exception
return: return from a Ruby method

Tracing is disabled within the context of proc.

  class Test
  def test
    a = 1
    b = 2
  end
  end

  set_trace_func proc { |event, file, line, id, binding, classname|
     printf "%8s %s:%-2d %10s %8s\n", event, file, line, id, classname
  }
  t = Test.new
  t.test

    line prog.rb:11               false
  c-call prog.rb:11        new    Class
  c-call prog.rb:11 initialize   Object
c-return prog.rb:11 initialize   Object
c-return prog.rb:11        new    Class
    line prog.rb:12               false
    call prog.rb:2        test     Test
    line prog.rb:3        test     Test
    line prog.rb:4        test     Test
  return prog.rb:4        test     Test

doc_ruby_on_rails

2025-01-10 15:47:30

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