Re: Viewing PDFs as text?

[Tim X]

Alan <lngndvs@gmail.com> writes:

> Less (via lesspipe, I think) is able to read pdf files as text, using
> pdftotext.  It would be much easier for me to browse pdfs using
> emacs.
>
> I would like to do this from dired.
>
> There is a doc-view.el facility, that seems too complicated for me.
> Did I misunderstand that, or is it possible in some other way to view
> pdfs from dired, as text?
>

doc-view will do what you want. However, if you just want a text version
of the file, you may find the following useful. this is my txutils.el
package. It converts various file types (doc, pdf, ps etc) to text or
sometimes html and then displays the output in an emacs buffer. I use
advice to attach this to view-file (v in dired). As an added benefit, if
you do a view file on an html file, it will render in w3m. 

Note that this works perfectly for me. Your milage may differ and you
may find bugs. I'm certanly happy to recieve bug reports, but cannot
guarantee a timely update/fix.

Tim

;;      Filename: /home/tcross/projects/emacs-convert/txutils.el
;; Creation Date: Wednesday, 20 September 2006 10:13 PM EST
;; Last Modified: Monday, 27 November 2006 06:38 PM EST
;;       Version: 2.0
;;        Author: Tim Cross 
;;   Description: Convert files from doc, ps, pdf, ppt to a format
;;                which can be viewed within emacs (i.e. text or html)

;;;
;;; This file is not part of GNU Emacs, but the same permissions apply.
;;; This file is released under the Free software foundation GPL. 
;;;
;;; GNU Emacs is free software; you can redistribute it and/or modify
;;; it under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 2, or (at your option)
;;; any later version.
;;;
;;; GNU Emacs is distributed in the hope that it will be useful,
;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Emacs; see the file COPYING.  If not, write to
;;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
;;;
;;; Commentary
;;; ==========
;;;
;;; The very simple idea behind this basic utility is to make accessing
;;; files in .doc, .pdf, .ps and .ppt more easily accessible without
;;; having to leave emacs or manually convert the file format prior
;;; to being able to view the contents in emacs.
;;;
;;; There are packages which will enable calls to external viewers
;;; for files of specific formats, such as xpdf for pdf etc. However,
;;; I wanted to have everything within emacs as this makes integration,
;;; cutting/pasting etc a lot easier, plus as a blind user, most
;;; external utilities are of little use because they don't also include
;;; speech support.
;;;
;;; The objective here is to have things setup so that when browsing
;;; a directory with dired, you can just hit 'v' for any file you want to
;;; view and you will be presented with a text or html version without
;;; needing to do any manual conversion - or even careing about what
;;; would need to be done.
;;;
;;; You need the following packages (or at least utilities which will
;;; do the same thing). Most of these are fairly standard with many Linux 
;;; distros these days. 
;;; The wv utilities which contain wvText for converting MS Word docs
;;; The xpdf utilities which include pdftotext for converting PDF to text
;;; The Ghostscript package which contains pstotext for converting PS to text
;;; The ppthtml utility for converting MS Power Point files to html
;;; A configured and working browse-url setup. I use w3m as my browser
;;;
;;; Customizing 
;;; ===========
;;;
;;; The easiest way to customize the conversion utility settings is to
;;; use M-x customize-group <RET> txutils <RET>
;;;
;;; In the txutils customize group, you will find just one setting, which
;;; is an alist of values indexed by a regular expression that matches against
;;; file extensions - a crude way of determining the source filetype
;;; (i.e. *.doc, *.pdf, *.ps, *.ppt, *.xls, *.html etc). See the
;;; documentation for more details.
;;;
;;; Installation 
;;; ============
;;; 
;;; Pretty straight forward. Place this file somewhere in your load path 
;;; and put a (require 'txutils) in your .emacs. You may want to byte
;;; compile this file.
;;;
;;; Thanks
;;; ======
;;;
;;; A number of people provided suggestions on how to improve both my elisp
;;; and the program itself. In particular, thanks goes to
;;; Lukas Loehrer
;;; Vinicius Jose Latorre
;;; Andreas Roehler
;;;
;;; plus a few others who gave general suggestions, feedback and
;;; encouragement. Thanks to everyone for taking the time and putting
;;; in the effort, its greatly appreciated.
;;; 
;;; Reporting Bugs
;;; ==============
;;; 
;;; This is the first bit of elisp I've allowed out into the world and 
;;; while I am really learning to love both elisp and cl lisp, I'm still 
;;; very much a novice. Therefore, there IS bugs and probably some pretty 
;;; poor style within this stuff. Feedback, bug reports and suggestions 
;;; always welcome. Send e-mail to tcross@une.edu.au
;;;

(require 'custom)
(require 'browse-url)

; make-temp-file is part of apel prior to emacs 22
(static-when (= emacs-major-version 21)
  (require 'poe))

(defgroup txutils nil
  "Customize group for txutils."
  :prefix "txutils-"
  :group 'External)

(defcustom txutils-convert-alist
  '( ;; MS Word
    ("\\.\\(?:DOC\\|doc\\)$"     doc  "/usr/bin/wvText"    nil nil nil nil nil)
    ;; PDF
    ("\\.\\(?:PDF\\|pdf\\)$"     pdf  "/usr/bin/pdftotext" nil nil nil nil nil)
    ;; PostScript
    ("\\.\\(?:PS\\|ps\\)$"       ps   "/usr/bin/pstotext"  "-output" t nil nil 
nil)
    ;; MS PowerPoint
    ("\\.\\(?:PPT\\|ppt\\)$"     ppt  "/usr/bin/ppthtml"   nil nil nil t t))

  "*Association for program convertion.

Each element has the following form:

(REGEXP SYMBOL CONVERTER SWITCHES INVERT REDIRECT-INPUT REDIRECT-OUTPUT 
HTML-OUTPUT)

Where:

REGEXP             is a regexp to match file type to convert.

SYMBOL             is a symbol to designate the fyle type.

CONVERTER          is a program to convert the fyle type to text or HTML.

SWITCHES           is a string which gives command line switches for the 
conversion 
               program. Nil means there are no switches needed.

INVERT             indicates if input and output program option is to be 
               inverted or not.  Non-nil means to invert, that is, output 
               option first then input option.  Nil means do not invert, 
               that is, input option first then output option.

REDIRECT-INPUT indicates to use < to direct input from the input
               file. This is useful for utilities which accept input
               from stdin rather than a file.

REDIRECT-OUTPUT indicates to use > to direct output to the output
               file. This is useful for utilities that only send output to 
               stdout.

HTML-OUTPUT    Indicates the conversion program creates HTML output 
               rather than plain text."

  :type '(repeat
          (list :tag "Convertion"
                (regexp  :tag "File Type Regexp")
                (symbol  :tag "File Type Symbol")
                (string  :tag "Converter")
                (choice  :menu-tag "Output Option"
                         :tag "Output Option"
                         (const :tag "None" nil)
                         string)
                (boolean :tag "Invert I/O Option")
                (boolean :tag "Redirect Standard Input")
                (boolean :tag "Redirect Standard Output")
                (boolean :tag "HTML Output")))
  :group 'txutils)

(defun txutils-run-command (cmd &optional output-buffer)
  "Execute shell command with arguments, putting output in buffer."
  (= 0 (shell-command cmd (if output-buffer
                              output-buffer
                            "*txutils-output*")
                          (if output-buffer
                              "*txutils-output*"))))

(defun txutils-quote-expand-file-name (file-name)
  "Expand file name and quote special chars if required."
  (shell-quote-argument (expand-file-name file-name)))

(defun txutils-file-alist (file-name)
  "Return alist associated with file of this type."
  (let ((al txutils-convert-alist))
    (while (and al 
                (not (string-match (caar al) file-name)))
      (setq al (cdr al)))
    (if al
        (cdar al)
      nil)))

(defun txutils-make-temp-name (orig-name type-alist)
  "Create a temp file name from original file name"
  (make-temp-file (file-name-sans-extension 
                   (file-name-nondirectory orig-name)) nil
                  (if (nth 7 type-alist)
                      ".html"
                    ".txt")))

(defun txutils-build-cmd (input-file output-file type-alist)
  "Create the command string from conversion alist."
  (let ((f1 (if (nth 3 type-alist)
                output-file
              input-file))
        (f2 (if (nth 3 type-alist)
                input-file
              output-file)))
    (concat
     (nth 1 type-alist)
     (if (nth 2 type-alist)               ; Add cmd line switches
         (concat " " (nth 2 type-alist)))
     (if (nth 4 type-alist)          ; redirect input (which may be output
         (concat " < " f1)           ; if arguments are inverted!)
       (concat " " f1))
     (if (nth 5 type-alist)          ; redirect output (see above comment)
         (concat " > " f2)
       (concat " " f2)))))

(defun txutils-do-file-conversion (file-name)
  "Based on file extension, convert file to text. Return name of text file"
  (interactive "fFile to convert: ")
  (let ((f-alist (txutils-file-alist file-name))
        output-file)
    (when f-alist
      (message "Performing file conversion for %s." file-name)
      (setq output-file (txutils-make-temp-name file-name f-alist))
      (message "Command: %s" (txutils-build-cmd file-name output-file f-alist))
      (if (txutils-run-command 
           (txutils-build-cmd (txutils-quote-expand-file-name file-name)
                              (txutils-quote-expand-file-name 
                               output-file) f-alist))
          output-file
        file-name))))

(defadvice view-file (around txutils pre act comp)
  "Perform file conversion or call web browser to view contents of file."
  (let ((file-arg (ad-get-arg 0)))
    (if (txutils-file-alist file-arg)
      (ad-set-arg 0 (txutils-do-file-conversion file-arg)))
    (if (string-match "\\.\\(?:HTML?\\|html?\\)$" (ad-get-arg 0))
        (browse-url-of-file (ad-get-arg 0))
      ad-do-it)))

(provide 'txutils)



-- 
tcross (at) rapttech dot com dot au