R/dcmtk_cmd_path.R

In muschellij2/dcmtk: Wrapper for 'DICOM' Toolkit ('DCMTK')

#' @title Get path for DCMTK command
#' @description Uses \code{Sys.which} to check if command is in the PATH.
#' @param cmd DCMTK command name
#' @return Logical \code{TRUE} if command is available.
#' @export
#' @examples
#' if (!have_dcmtk_cmd("dcmodify")) {
#' install_dir = tempdir()
#' options(dcmtk.path = install_dir)
#'   res = try({
#'     install_dcmtk(install_dir = install_dir)
#'   })
#'   if (inherits(res, "try-error")) {
#'     res = FALSE
#'   }
#'   if (!res) {
#'     source_install_dcmtk(install_dir = install_dir)
#'   }
#' }
#' dcmtk_cmd("dcmodify")
dcmtk_cmd_path = function(cmd){

  # putting in the exe for Windows
  sysname = tolower(Sys.info()["sysname"])
  if (sysname %in% "windows") {
    ext = tools::file_ext(cmd)
    if (ext == "") {
      cmd = paste0(cmd, ".exe")
    }
  }

  check_cmd = Sys.which(cmd)
  if (check_cmd == "") {
    dcmtk_dir = getOption("dcmtk.path")
    if (!is.null(dcmtk_dir)) {
      check_cmd = file.path(dcmtk_dir, "bin", cmd)
      if (!file.exists(check_cmd)) {
        check_cmd = ""
      }
    }
    if (check_cmd == "") {
      check_cmd = system.file("bin", cmd, package = "dcmtk")
    }
  }
  if (sysname %in% "windows") {
    check_cmd = gsub("\\\\", "/", check_cmd)
    check_cmd = gsub("\\\\", "/", check_cmd)
  }
  if (is.null(check_cmd)) {
    check_cmd = ""
  }
  return(check_cmd)
}