;; cat.lisp: lisp function implementing Unix "cat". (brg 15-Mar-2003)
;; illustrates use of "dolines" macro.  Much simpler than standard cat(1).

(defmacro dolines (initform &rest body)
 (let ((linevar (car initform))
       (streamvar (cadr initform)))
  `(do ((,linevar (read-line ,streamvar nil) (read-line ,streamvar nil)))
       ((null ,linevar) ,@(cddr initform))
     ,@body)))

(defun cat-single-file (filename)
	(with-open-file (fstr filename)
		(dolines (l fstr)
          (write-line l))))

(defun cat-list (filenames)
	(if (not (null filenames))
		(progn
			(cat-single-file (car filenames))
			(cat-list (cdr filenames)))
		(values)))

(defun cat (&rest filenames)
	(cat-list filenames))