convert legacy xls files to xlsx files

convert_to_xlsx.R

library(purrr)

xls_to_xlsx  <- function(file) {
  if (fs::path_ext(file) != "xls") {
    stop("file must have extension xls")    
  }
  
  sheets <- readxl::excel_sheets(file)
  
  insheets <- map(sheets, ~readxl::read_excel(file, .x, col_names = FALSE))
  insheets <- set_names(insheets, sheets)
  
  outfile <- fs::path_ext_set(file, "xlsx")
  writexl::write_xlsx(insheets, outfile, col_names = FALSE)
}