How to Flush Output Buffer in Ruby?

[Ubuntist]

I'm debugging a Monte Carlo simulation written in Ruby. At the beginning of each Monte Carlo trial, my code does a

puts trialNum

where trialNum is the iteration counter. Unfortunately, this output often fails to appear in until the program has finished running. I guess the output is being buffered. Is there a way to flush the buffer, so that these little progress reports appear in real time?

[geraldm]

puts trialNum
$stdout.flush # (depends on OS, but should work)

[Ubuntist]

Yo, dude, thanks! It works a treat.

[santi740]

didnt work for me, i get this error

cliente.rb:16: undefined local variable or method `stdout' for main:Object (NameError)

[stylishpants]

didnt work for me, i get this error

cliente.rb:16: undefined local variable or method `stdout' for main:Object (NameError)

It's $stdout, not stdout.