add a function format_bytes() borrowed from tinytex:::auto_size() and…

… built on top of format.object_size()

NAMESPACE

@@ -30,6 +30,7 @@ export(exit_call)
 export(file_exists)
 export(file_ext)
 export(file_string)
+export(format_bytes)
 export(from_root)
 export(github_releases)
 export(grep_sub)

NEWS.md

@@ -4,6 +4,8 @@
 
 - Added a `news2md()` function to convert package news to the Markdown format. This is mainly for converting the plain-text `NEWS` file and the `NEWS.Rd` file to `NEWS.md`.
 
+- Added a `format_bytes()` function to format numbers of bytes using a specified unit, e.g., `1024` can be formatted as `1 Kb`.
+
 - When using `pkg_load2()` in an **renv** project, it will use `renv::install()` to install missing packages by default to take advantage of **renv**'s caching feature (thanks, @chunyunma @cderv, #52).
 
 - `upload_win_builder()` no longer requires the system command `curl` to be available; if `curl` is not available, the R package **curl** will be used instead, which means this R package must be installed. In addition to uploading to the `ftp` server of win-builder, it's also possible to upload to <https://win-builder.r-project.org/upload.aspx>: call `upload_win_builder(..., server = 'https')`. This change was made so that it would be possible to continue to upload to win-builder in case it should stop supporting `ftp` (CRAN has discouraged package authors from using `ftp://`).

R/utils.R

@@ -260,3 +260,19 @@ connect_pipes = function(x) {
 }
 
 pkg_file = function(...) system.file(..., package = 'xfun', mustWork = TRUE)
+
+#' Format numbers of bytes using a specified unit
+#'
+#' Call the S3 method \code{format.object_size()} to format numbers of bytes.
+#' @param x A numeric vector (each element represents a number of bytes).
+#' @param units,... Passed to \code{\link[=format.object_size]{format}()}.
+#' @return A character vector.
+#' @export
+#' @examples
+#' xfun::format_bytes(c(1, 1024, 2000, 1e6, 2e8))
+#' xfun::format_bytes(c(1, 1024, 2000, 1e6, 2e8), units = 'KB')
+format_bytes = function(x, units = 'auto', ...) {
+  vapply(x, function(b) {
+    format(structure(b, class = 'object_size'), units = units, ...)
+  }, character(1))
+}