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I need to get weblinks from a buffer (http....) and put them into scratch buffer. This code partially works, but the weblinks are inserted in the same buffer.

I'm new at programming.

(defun get-weblinks ()
  "Get weblinks from a buffer"
  (interactive)
  (let (p1 p2 url)
    (while (search-forward "http")
      (backward-char 4)
      (setq p1 (point))
      (search-forward "jpg")
      (setq p2 (point))
      (setq url (buffer-substring p1 p2))
      (insert url "\n")
      )))

How can I finish the function?

Thank you for your help.

Drew
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Lizardo Reyna
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  • The solution will likely entail either re-search-forward or re-search-backward with an appropriate regex that matches the entire link; and then use (match-beginning 0) and (match-end 0) to get the points for the beginning and ending of the link -- assuming the regex matches everything. You can use M-x re-builder to come up with a complete regexp; or you can Google for it and then check with re-builder to see if it matches them all. I saw several examples in my brief Google searches dealing with the generalized type of links with href or src, so you'll need to do some hunting. – lawlist Dec 03 '15 at 22:40
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    You can push the results into a list and then regurgitate the list when your all done -- e.g., (let (result my-list) ... *while* search stuff (setq result "thelink") (push result my-list) ... move to wherever or whatever buffer ... (mapc (lambda (x) (insert x "\n")) my-list)) – lawlist Dec 03 '15 at 22:50
  • This is the improved function. It is ok for now. The weblinks are printed line by line in message buffer. 
    (defun get-weblinks ()
  (interactive)
  (let (p1 p2 url)
    (while (re-search-forward "http.+jpg" nil t)
       (setq p1 (match-beginning 0))
        (setq p2 (match-end 0))
        (message (buffer-substring p1 p2) "\n")
         )))

    This is very useful to me.

    Thank you. @lawlist

     – Lizardo Reyna Dec 04 '15 at 11:08

1 Answers1

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(defun get-weblinks ()
"Goto the beginning of the current buffer; perform the search and store the links;
go back to the point of origin; create a new buffer; iterate over the list and insert
the links into the new buffer; switch to the new buffer; go to the beginning of the
new buffer."
(interactive)
  (let (url-list)
    (save-excursion
      (goto-char (point-min))
      (while (re-search-forward "http.+jpg" nil t)
        (push
          (buffer-substring-no-properties (match-beginning 0) (match-end 0))
          url-list)))
    (with-current-buffer (get-buffer-create "*URL*")
      (mapc
        (lambda (url)
          (insert url "\n"))
        url-list))
    (switch-to-buffer (get-buffer "*URL*"))
    (goto-char (point-min))))
lawlist
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  • wow.. It works perfect, it is a very useful function to me. I'm motivated to learn more emacs. I will analyze your code to understand step by step. Thank you very much. – Lizardo Reyna Dec 05 '15 at 07:03
  • Nice, always something to learn from @lawlist code, thank you. – gsl Dec 05 '15 at 08:39