.gsub_files<-xfun::gsub_files .gsub_dir<-xfun::gsub_dir .gsub_ext<-xfun::gsub_ext## Change the working directory, evaluate the expression,## and restore the working directory.move_run<-xfun::in_dir## Install a source package from a directory.install_dir<-xfun::install_dir## Chec...