(shell-quote-argument): New function.

lisp/subr.el

@@ -643,6 +643,18 @@ Wildcards and redirection are handle as usual in the shell."
            (cons 'progn body)
            (list 'store-match-data original)))))
 
+(defun shell-quote-argument (argument)
+  "Quote an argument for passing as argument to an inferior shell."
+  ;; Quote everything except POSIX filename characters.
+  ;; This should be safe enough even for really weird shells.
+  (let ((result "") (start 0) end)
+    (while (string-match "[^---0-9a-zA-Z_./]" argument start)
+      (setq end (match-beginning 0)
+	    result (concat result (substring argument start end)
+			   "\\" (substring argument end (1+ end)))
+	    start (1+ end)))
+    (concat result (substring argument start))))
+
 ;; now in fns.c
 ;(defun nth (n list)
 ;  "Returns the Nth element of LIST.