Re: [Sbcl-devel] scripting sbcl (correction)

[Joseph S. <ten...@ya...>]

Hi,

I made an error in that NIL is not of type STRING if
the script is run with no args. My mistake. Here's the
corrected script.

Regards,

Joe

#!/usr/local/bin/sbcl --noinform
;; prime-example.lisp adapted from clisp forums
;;; using SBCL instead of CLISP

(defun primep (x)
"Predicate to test the primes of x."
(let ((sqrt-x (sqrt x)))
  (do ((i 2 (1+ i)))
	((> i sqrt-x) t)
	(when (eq (mod x i) 0)
	  (return nil)))))

(defun find-primes (m n)
"Find and print n prime numbers greater than m."
(do ((i (1+ m) (1+ i))
	(found 0))
	((>= found n) t)
	(when (primep i)
	(format t "~A~%" i)
	(incf found))))

(defun print-usage-info ()
"Print usage hints for this script."
(format t "Usage: primes <M> <N>~%")
(format t "Description: Print first N prime numbers
greter than M.~%")
(format t "Note: Both arguments M and N must be
integers.~%"))

(defun main (sb-ext:*posix-argv*)
"Main function to analyze command-line args"
;(if (null (second sb-ext:*posix-argv*)) ; script-name
not given?
; more correct would be to test if args list is empty
(if (null (and (third sb-ext:*posix-argv*)(fourth
sb-ext:*posix-argv*))) ; an empty list would be of a
wrong type here, use simple 'and' instead
	(print-usage-info)
	;(let ((arg1 (parse-integer (first
sb-ext:*posix-argv*) :junk-allowed t))
    (let ((arg1 (parse-integer (third
sb-ext:*posix-argv*) :junk-allowed t))
	;(arg2 (parse-integer (second sb-ext:*posix-argv*)
:junk-allowed t)))
    (arg2 (parse-integer (fourth sb-ext:*posix-argv*)
:junk-allowed t)))
	(if (and (integerp arg1)
		(integerp arg2))
	(find-primes arg1 arg2)
	(print-usage-info)))))

(compile 'find-primes)
(compile 'primep)
(main sb-ext:*posix-argv*)



       
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