method

caller

v2_1_10 - Show latest stable - Class: Kernel
caller(*args)
public

Returns the current execution stack—an array containing strings in the form file:line or file:line: in `method’.

The optional start parameter determines the number of initial stack entries to omit from the top of the stack.

A second optional length parameter can be used to limit how many entries are returned from the stack.

Returns nil if start is greater than the size of current execution stack.

Optionally you can pass a range, which will return an array containing the entries within the specified range.

def a(skip)
  caller(skip)
end
def b(skip)
  a(skip)
end
def c(skip)
  b(skip)
end
c(0)   #=> ["prog:2:in `a'", "prog:5:in `b'", "prog:8:in `c'", "prog:10:in `<main>'"]
c(1)   #=> ["prog:5:in `b'", "prog:8:in `c'", "prog:11:in `<main>'"]
c(2)   #=> ["prog:8:in `c'", "prog:12:in `<main>'"]
c(3)   #=> ["prog:13:in `<main>'"]
c(4)   #=> []
c(5)   #=> nil

1Note

Reports originally defined method names, not invoked names in Ruby 1.9.x

stevecj · Sep 10, 2012

In Ruby 1.8.7, the reported method names were those of the methods actually invoked, so if #b was an alias for #a, and #b was called, it would be reported as "... in b'". In Ruby 1.9, the same invocation is now reported as "... in a'".

Unfortunately, this change disables the hack that could formerly be used to create a variant of method that returns the method as actually invoked. The new callee method is no help with that, because it is currently synonymous with method.