Configurable Progress bars, they may include percentage, elapsed time,
and/or the estimated completion time. They work in terminals, in 'Emacs'
'ESS', 'RStudio', 'Windows' 'Rgui' and the 'macOS' 'R.app'.

The package also provides a 'C++' 'API', that works with or without 'Rcpp'.

WWW: https://cran.r-project.org/web/packages/progress/