dir <- commandArgs(trailingOnly = TRUE)[1]
files <- sort(list.files(dir, pattern = "\\.rds$", full.names = TRUE))
for (f in files) {
  x <- readRDS(f)
  nm <- sub("\\.rds$", "", basename(f))
  describe <- function(d) sprintf("[%dx%d] %s", nrow(d), ncol(d), paste(names(d), collapse=","))
  if (is.data.frame(x)) {
    cat(sprintf("%-14s df  %s\n", nm, describe(x)))
  } else if (is.list(x) && !is.null(x$sim)) {
    cat(sprintf("%-14s list sim=%s | sim.ss=%s\n", nm,
                sprintf("[%dx%d]", nrow(x$sim), ncol(x$sim)),
                sprintf("[%dx%d]", nrow(x$sim.ss), ncol(x$sim.ss))))
  } else {
    cat(sprintf("%-14s %s\n", nm, class(x)))
  }
}