R/history.R

In BrailleR: Improved Access for Blind Users

# as supplied by Duncan Murdoch
# is pretty much the utils::history with use of file.edit() at the end.

history =
    function(max.show = 25, reverse = FALSE, pattern, ...) {
      file1 <- tempfile("Rrawhist")
      savehistory(file1)
      rawhist <- readLines(file1)
      unlink(file1)
      if (!missing(pattern))
        rawhist <- unique(grep(pattern, rawhist, value = TRUE, ...))
      nlines <- length(rawhist)
      if (nlines) {
        inds <- max(1, nlines - max.show):nlines
        if (reverse) inds <- rev(inds)
      } else
        inds <- integer()
      file2 <- tempfile("hist")
      writeLines(rawhist[inds], file2)
      file.edit(file2)
    }