I was writing some tests around a Ruby library (day-job stuff) and needed some way to look at the debug output of the library. Since debug output is spewed to stdout and hacking up the library wasn't really feasible, I needed some way to get hold of stdout programmatically.
Temporarily redirect stdout into something the sort of looks like an output stream.
class StdOutCapturer attr_reader :output def initialize @output = "" end def write(s) @output += s end end def get_stdout(func, *params) orig_stdout = $stdout my_stdout = StdOutCapturer.new() $stdout = my_stdout result = func.call(*params) $stdout = orig_stdout return my_stdout.output, result end
It is used like so:
txt, result = get_stdout(self.method("puts"), "foo")