; grep - Globally seek Regular Expression and Print (or whatever...)
; search a set of files for text matching a regular expression, and print that text
;
; 6-nov-1999 goetter READ-STRING now returns eof object instead of #f at EOF
; 2-oct-2000 goetter print filename
; 4-may-2005 port to 1.2

(require "regex.dll")

(define (grep exp dir wild)
  (letrec ((re (regex exp 'no-values))
           (grepper
             (lambda (file)
               (call-with-input-file file
                 (lambda (f)
                   (do ((l (read-string f) (read-string f)))
                     ((eof-object? l) 'done)
                     (if (regex-match re l) 
                       (for-each (lambda (x) (display x))
                         (list file ":" l))))))) ))
    (for-each 
      (lambda (f) (grepper (string-append dir (if (string=? dir "\\") "" "\\") f)))
      (directory-list dir wild 18))))

(define (input prompt default)
  (let ((l (begin (display prompt) (force-output) (read-line))) )
   (cond
    ((eof-object? l) (exit))
    ((> (string-length l) 0) l)
    ((not (null? default)) default)
    (else (input prompt default)) )))

(let ((expression (input "Enter regular expression (don't forget to escape metachars): " '()))
      (directory (input "Directory: " ""))
      (filepat (input "Pattern of files to search: " "*")) )

 (grep expression directory filepat))

(display "** Press ENTER to close.")
(read-line)