osx - txtProgressBar not updating on Mac R Console -

osx - txtProgressBar not updating on Mac R Console -

my r (3.0.2) console doesn't update txtprogressbar until code has executed (defeating purpose of progress bar). i've been running following:

pb <- txtprogressbar(0, 20, 0) (i in 1:20) { sys.sleep(0.5) settxtprogressbar(pb, i) }

nothing output 10 seconds (the time execute whole code segment) , entire progress bar printed out. behavior doesn't alter if add together flush.console() phone call after settxtprogressbar call.

i suspect mac r console-specific, progress bar works expected in linux r console. how can expected progress bar behavior?

r osx progress-bar