在bash脚本中运行时，使R（统计包）等待键盘提示

I am using R to generate a series of plots within a loop, with the user hitting the enter key to indicate they have seen the plot and it is time to move on. These are interactive rotatable plots generated with the rgl package and therefore using something like Sys.sleep() is not good enough.I am using R to generate a series of plots with