R/getLastModifiedFile.R

In Sumpfohreule/MyUtilities: Collection of general functions which are useful in multiple contexts

#' Returns path for the most recent modified file
#'
#' Within a given folder path the path to the file with the most recent changes
#' is returned
#'
#' @param folder Path to the folder, containing the files to select from
#' @param pattern A regex pattern to select files by
#' @param recursive Flag to determine if folders should be included recursively
#' @return Returns path of a single file which was modified most recently. Error
#' is thrown if none was found!
#' @export
#'
getLastModifiedFile <- function(folder, pattern = NULL, recursive = FALSE) {
  latest_file <- data.frame(path = dir(folder,
    full.names = TRUE,
    pattern = pattern,
    recursive = recursive
  )) %>%
    dplyr::mutate_all(as.character) %>%
    # Filter folders
    dplyr::filter(!dir.exists(path)) %>%
    # Filter excel lock files
    dplyr::filter(!stringr::str_detect(basename(path), pattern = "^~\\$")) %>%
    dplyr::filter(file.mtime(path) == max(file.mtime(path))) %>%
    dplyr::pull(path)
  if (file.exists(latest_file)) {
    return(latest_file)
  } else {
    stop(
      "No files have been found with the given pattern '", pattern,
      "' within folder\n", folder
    )
  }
}