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  1. (defparameter *my-readtable* (copy-readtable))
  2.  
  3. (defun my-sharp-dot-reader (stream &rest _)
  4.   (declare (ignore _))
  5.   (let ((expr (read stream)))
  6.     (list 'quote expr)))
  7.  
  8. (let ((*readtable* *my-readtable*))
  9.   (set-dispatch-macro-character #\# #\. #'my-sharp-dot-reader))
  10.  
  11. (defun safe-read ()
  12.   (let ((*readtable* *my-readtable*))
  13.     (read)))
  14.  
  15. (setf b (safe-read))
  16. (princ b))
Runtime error #stdin #stdout 0.03s 10792KB
comments (?)
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#.(progn (format t "Oh, exploitable!~%") '(+ 2 2))
stdout
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'(PROGN (FORMAT T Oh, exploitable!~%) '(+ 2 2))
https://ideone.com/UUsLN
language:
Common Lisp (clisp 2.49.92)
created:
13 years ago
visibility:
public

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