whereami.R

#' @title Return where the script is run from
#' @description Returns the file that a command is run from.
#'
#' If traceback is available then the line that it was run from is also returned.
#' @param path_expand logical, expand relational path, Default: FALSE
#' @param tag character, optional tag for the call, Default: NULL
#' @return character
#' @examples
#'  whereami()
#'  whereami(path_expand = TRUE)
#' @rdname whereami
#' @export
#' @family main
#' @author Jonathan Sidi
#' @importFrom rstudioapi getActiveDocumentContext isAvailable
#' @importFrom utils getSrcDirectory getSrcFilename
whereami <- function(path_expand = FALSE, tag = NULL) {

  tf <- tempfile()

  on.exit({
    if (length(ret) > 1) {
      bump(ret, tag)
    }

    unlink(tf)
  }, add = TRUE)

  cmd <- commandArgs(trailingOnly = FALSE)

  if (any("RStudio" %in% cmd)) {
    src <- "Untitled"

    adc <- rstudioapi::getActiveDocumentContext()

    if (adc$id == "#console") {
      src <- "Console"
    }

    if (nchar(adc$path) > 0) {
      src <- path.expand(adc$path)
    }

    if (length(getSrcFilename(sys.call(sys.nframe() - 1))) > 0) {
      if (nchar(getSrcFilename(sys.call(sys.nframe() - 1))) > 0) {
        src <- file.path(
          utils::getSrcDirectory(sys.call(sys.nframe() - 1)),
          utils::getSrcFilename(sys.call(sys.nframe() - 1))
        )

        src <- gsub("^\\.", getwd(), src)
      }
    }

    if (!path_expand) {
      src <- path_reduce(src)
    }

    cat(src, file = tf, sep = "\n")

  } else {
    src <- thisfile()

    if (!is.null(src)) {
      src <- normalizePath(src,winslash = '/', mustWork = FALSE)

      if (!path_expand) {
        src <- path_reduce(src)
      }
    } else {
      cat("", file = tf, sep = "\n", append = TRUE)
    }

    if (!is.null(src)) {
      cat(src, file = tf, sep = "\n", append = TRUE)
    }
  }

  refloc <- crumb()

  if (!is.null(refloc)) {
    cat(refloc, file = tf, sep = "\n", append = TRUE)
  }

  ret <- readLines(tf)

  structure(ret, class = c("whereami","character"))
}