Add support for R_STARTUP_RDATA={default,rename,remove,prompt} [#42]

NEWS

@@ -3,6 +3,16 @@ Package: startup
 
 Version: 0.13.0-9000 [2019-12-03]
 
+NEW FEATURES:
+
+ * Setting environment variable 'R_STARTUP_RDATA' to "remove" will cause an
+ existing './.RData' file to be skipped by automatically removing it.
+ If "rename", it will be renamed to './.RData-YYYYMMDD_hhmmss' where the
+ timestamp is the last time the file was modified. If "prompt", then the
+ user is prompted whether they want to load the file or rename it. Thus,
+ setting 'R_STARTUP_RDATA=rename' in an .Renviron file will make sure no
+ .RData file is ever loaded while still preserving them.
+
 BUG FIXES:
 
  * startup(all = TRUE) would process startup folders in the current working

R/startup.R

@@ -92,9 +92,10 @@ startup <- function(sibling = FALSE, all = FALSE,
 
  debug(debug)
 
+ cmd_args <- getOption("startup.debug.commandArgs", commandArgs())
+
  debug <- debug()
  if (debug) {
- cmd_args <- getOption("startup.debug.commandArgs", commandArgs())
  r_home <- R.home()
  r_arch <- .Platform$r_arch
  r_os <- .Platform$OS.type
@@ -256,24 +257,85 @@ startup <- function(sibling = FALSE, all = FALSE,
  logf("- Search path: %s", paste(sQuote(search()), collapse = ", "))
  logf("- Loaded namespaces: %s",
  paste(sQuote(loadedNamespaces()), collapse = ", "))
-
- interactive <- interactive()
-
  logf("startup::startup()-specific processing ... done")
  logf("The following will be processed next by R:")
+ }
+
+ no_restore_data <- any(c("--no-restore-data", "--no-restore", "--vanilla") %in% cmd_args)
+ loads_RData <- has_RData <- FALSE
+ if (!no_restore_data) {
+ has_RData <- is_file(f <- "./.RData")
+ if (has_RData) {
+ f_info <- file_info(f, type = "binary")
+ env <- Sys.getenv("R_STARTUP_RDATA", "")
+ if (env == "") {
+ env <- "default"
+ } else if (debug) {
+ logf("- R_STARTUP_RDATA=%s", env)
+ }
+
+ if (env == "prompt") {
+ logf("- Prompting user whether they want to load %s or not", f_info)
 
- no_restore_data <- any(c("--no-restore-data", "--no-restore", "--vanilla") %in% cmd_args)
- loads_RData <- FALSE
+ prompt <- sprintf("Detected %s - do you want to load it? If not, it will be renamed. [Y/n]: ", f_info)
+ res <- TRUE
+ repeat({
+ ans <- readline(prompt)
+ ans <- gsub("(^[[:space:]]*|[[:space:]]*$)", "", ans)
+ ans <- tolower(ans)
+ if (ans %in% c("", "y", "yes")) {
+ res <- TRUE
+ break
+ } else if (ans %in% c("n", "no")) {
+ res <- FALSE
+ break
+ }
+ })
+ logf("- User wants to load it: %s", res)
+ env <- if (res) "default" else "rename"
+ }
+
+ if (env == "remove") {
+ logf("- Skipping %s by removing it", f_info)
+ file.remove(f)
+ has_RData <- is_file(f)
+ if (!has_RData) {
+ warning(sprintf("Skipped %s because R_STARTUP_RDATA=%s caused it to be removed", f, env), call. = FALSE)
+ }
+ } else if (env == "rename") {
+ fi <- file.info(f)
+ when <- fi[c("mtime", "ctime")]
+ keep <- vapply(when, FUN = inherits, "POSIXct", FUN.VALUE=FALSE)
+ when <- when[keep]
+ when <- sort(when, decreasing = TRUE)
+ when <- format(when[[1]], format = "%Y%m%d_%H%M%S")
+ f_new <- sprintf("%s.%s", f, when)
+ file.rename(f, f_new)
+ f_new_info <- file_info(f_new, type = "binary")
+ logf("- Skipping %s by renaming it to %s", f, f_new_info)
+ has_RData <- is_file(f)
+ if (!has_RData) {
+ warning(sprintf("Skipped %s because R_STARTUP_RDATA=%s caused it to be renamed to %s", f, env, f_new_info), call. = FALSE)
+ }
+ } else if (env != "default") {
+ warning(sprintf("Ignoring unknown value (%s) of %s",
+ sQuote(env), sQuote("R_STARTUP_RDATA")),
+ call. = FALSE)
+ }
+ }
+ }
+
+ if (debug) {
  if (!no_restore_data) {
- if (is_file(f <- "./.RData")) {
+ if (has_RData) {
  loads_RData <- TRUE
  logf("- %s", file_info(f, type = "binary"))
  }
  }
 
  logf("- R_HISTFILE: %s", sQuote(Sys.getenv("R_HISTFILE")))
  no_restore_history <- any(c("--no-restore-history", "--no-restore", "--vanilla") %in% cmd_args)
- if (!no_restore_history && interactive) {
+ if (!no_restore_history && interactive()) {
  if (is_file(f <- Sys.getenv("R_HISTFILE", "./.Rhistory"))) {
  logf("- %s", file_info(f, type = "txt"))
  }