 Use POST-PROCESS-TEMPLATE to further expand template given own logic.
 
 Set TEMP-DIR to a unique temp directory to this template."
-  (cl-assert (not (and (dwim-shell-command--contains-multi-file-refs template)
+  (cl-assert (not (and (dwim-shell-command--contains-multi-file-ref template)
                        (dwim-shell-command--contains-single-file-ref template)))
              nil "Must not have %s and %s in the same template"
-             (dwim-shell-command--contains-multi-file-refs template)
+             (dwim-shell-command--contains-multi-file-ref template)
              (dwim-shell-command--contains-single-file-ref template))
   (setq files (seq-map (lambda (file)
                          (expand-file-name file))

         (progress-reporter))
    (if (seq-empty-p files)
        (setq script template)
      (if (dwim-shell-command--contains-multi-file-refs template)
          (setq script (dwim-shell-command--expand-files-template template files post-process-template gen-temp-dir))
        (seq-do (lambda (file)
                  (setq script

  (when (or gen-temp-dir (string-match-p "\<\<td\>\>" script 0))
    (setq gen-temp-dir (make-temp-file "dwim-shell-command-" t)))
  (when (seq-empty-p files)
    (cl-assert (not (or (dwim-shell-command--contains-multi-file-ref script)
                        (dwim-shell-command--contains-single-file-ref script)))
               nil "No files found to expand %s"
               (or (dwim-shell-command--contains-multi-file-ref script)
                   (dwim-shell-command--contains-single-file-ref script))))
  (when extensions
    (seq-do (lambda (file)
