Merge pull request #2040 from jeongoon/ch-072

add a solution of common-lisp for task 2

1 files changed, 51 insertions, 0 deletions

diff --git a/challenge-072/jeongoon/common-lisp/ch-2.lsp b/challenge-072/jeongoon/common-lisp/ch-2.lsp
new file mode 100644
index 0000000000..c1e960d8fd
--- /dev/null
+++ b/challenge-072/jeongoon/common-lisp/ch-2.lsp
@@ -0,0 +1,51 @@
+;; Ref:
+;; http://www.gigamonkeys.com/book/files-and-file-io.html
+;; http://cl-cookbook.sourceforge.net/files.html#open
+;; http://www.ai.sri.com/pkarp/loop.html
+
+(defun get-command-line ()
+  (or
+   #+CLISP *args*
+   #+SBCL *posix-argv*
+   #+LISPWORKS system:*line-arguments-list*
+   #+CMU extensions:*command-line-words*
+   nil))
+
+(defparameter *cmdline* (get-command-line))
+
+(defun print-usage ()
+  (format t "Usage: sbcl --script ch-2.lsp <file-path> <from> <to>~%" (car *cmdline*)))
+
+(when (not (= (length *cmdline*) 4)) ;; not 3
+  (format t "Wrong Number of arguments got ~d: not 3~%" (length *cmdline*))
+  (print-usage)
+  (quit))
+
+(defparameter *file-path* (nth 1 *cmdline*))
+(defparameter *from*      (parse-integer (nth 2 *cmdline*)))
+(defparameter *to*        (parse-integer (nth 3 *cmdline*)))
+
+(when (not (probe-file *file-path*))
+  (format t "Could not read the file ~a~%" *file-path*)
+  (quit))
+
+(when (not (and (numberp *from*) (numberp *to*)))
+  (format t "given numbers are not in the range: from ~a, to ~a" *from* *to*)
+  (quit))
+
+(format t "[INF] File: ~a: from: ~d to: ~d~%" *file-path* *from* *to*)
+
+(with-open-file
+ (in *file-path* :if-does-not-exist nil) ;; return nil instead of error
+ (loop for line = (read-line in nil)
+       for cnt from 1  ;; cool auto counter
+
+       while line do   ;; I don't know whay parenthesis is not used here.
+                       ;; look like a macro for something
+       (progn
+         (when (and (<= *from* cnt) (<= cnt *to*))
+           (format t "~a~%" line))
+         (when (= cnt *to*)
+           (format t "[INF] Done.~%")
+           (return "[done]"))
+         (setq cnt (+ 1 cnt)))))