Display line number in emacs

1. download linum.el form http://www.emacswiki.org/emacs/line-num.el copy to ~/library/elisp

 

2. start emacs and add content

    C-x C-f ~/.emacs

 ; display line number
(add-to-list 'load-path "~/library/elisp/")
(load "linum.el")
(require 'linum)
(global-linum-mode 1)

; enable erase buffer command
(put 'erase-buffer 'disabled nil)

; set tab to 4 space
(setq-default indent-tabs-mode nil)
(setq-default tab-width 4)

;next

 

3. restart emacs

 

 

4. linum.el

---

;;; line-num.el --- Display line numbers in left-margin of buffer.

;;

;; Filename: line-num.el

;; Description: Display line numbers in left-margin of buffer.

;; Author: (Darryl Okahata) darrylo@hpsrdmo, Drew Adams

;; Maintainer: Drew Adams

;; Copyright (C) 1999-2010, Drew Adams, all rights reserved.

;; Copyright (C) 1989, Hewlett-Packard, all rights reserved.

;; Created: Wed Mar 31 16:18:24 1999

;; Version: 21.0

;; Last-Updated: Fri Jan 15 13:25:23 2010 (-0800)

;;           By: dradams

;;     Update #: 208

;; URL: http://www.emacswiki.org/cgi-bin/wiki/line-num.el

;; Keywords: local

;; Compatibility: GNU Emacs: 20.x, 21.x, 22.x, 23.x

;;

;; Features that might be required by this library:

;;

;;   None

;;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;

;;; Commentary:

;;

;;    Display line numbers in left-margin of buffer.

;;

;; New functions defined here:

;;

;;    `display-line-numbers', `toggle-line-numbers-display',

;;    `turn-on-line-numbers-display', `turn-off-line-numbers-display'.

;;

;; NOTE: `setnu.el' now provides similar, but generally better,

;; functionality.

;;

;; Original author was Darryl Okahata darrylo@hpsrdmo: The copy on

;; which the current (Adams) modifications were made was obtained from

;; Rick Kunin (rickk@sperdk).

;;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;

;;; Change log:

;;

;; 2004/11/26 dadams

;;     Replaced decf with setq...1+.

;;     turn-off-line-numbers-display: Error if not displaying line #s.

;;     Removed calls to `fit-frame' (and require of fit-frame.el).

;; 2000/11/01 dadams

;;     1. Added: toggle-line-numbers-display, turn-on-line-numbers-display,

;;               turn-off-line-numbers-display.

;;     2. Added global vars: displaying-line-numbers-p,

;;        display-line-numbers-format-string, display-line-numbers-first-line,

;;        display-line-numbers-count, display-line-numbers-buffer-name,

;;        display-line-numbers-modified-p.

;; 1999/04/14 dadams

;;     Commented out assignment to unused free var: insert-end.

;;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;

;; This program 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.



;; This program 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 this program; see the file COPYING.  If not, write to

;; the Free Software Foundation, Inc., 51 Franklin Street, Fifth

;; Floor, Boston, MA 02110-1301, USA.

;;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;

;;; Code:



;;>> Problem:  Tabs at beginning of lines





(and (< emacs-major-version 20) (eval-when-compile (require 'cl))) ;; when, unless



;;;;;;;;;;;;;





;;;###autoload

(defun display-line-numbers ()

  "Temporarily display line numbers in left margin of current buffer."

  (interactive)

  (or (eq (current-buffer) (window-buffer (selected-window)))

      (error "Current buffer, %s, is not the selected window's buffer"

             (buffer-name)))

  (let ((buffer-read-only nil)

        (modified (buffer-modified-p))

        (name buffer-file-name)

        (point (point-marker))

        format-string

        line-number

        (count 0)

        nlines

        first-line)

    (save-restriction

      (widen)

      (save-excursion

        (setq first-line (window-start (selected-window)))

        (goto-char first-line)

        (setq line-number (1+ (count-lines (point-min) (point))))

        (move-to-window-line -1)

        (beginning-of-line)

        (setq nlines (count-lines first-line (point)))

        (let ((max (+ line-number nlines)))

          (setq format-string (cond ((< max 100) "%2d ")

                                    ((< max 1000) "%3d ")

                                    ((< max 10000) "%4d ")

                                    (t "%7d "))))))

    (save-excursion

      (unwind-protect

          (progn

            (goto-char first-line)

            ;; defeat file locking... don't try this at home, kids!

            (setq buffer-file-name nil)

            (while (<= count nlines)

              (insert-before-markers (format format-string line-number))

              ;;;(setq insert-end (point)) THIS VAR IS FREE - AND UNUSED!

              (setq line-number (1+ line-number))

              (setq count (1+ count))

              (forward-line 1))

            (set-window-start (selected-window) first-line)

            (goto-char point)

            (set-buffer-modified-p modified)

            (message "<<< Press SPACE to continue >>>")

            (let ((char (read-char)))

              (or (eql char ?/  )

                  (setq unread-command-events (list char))))

            )

        (goto-char first-line)

        (let ((n (1+ (- (aref format-string 1) ?0))))

          (while (> count 0)

            (setq count (1- count))

            (delete-char n)

            (forward-line 1)))

        (setq buffer-file-name name)

        (set-buffer-modified-p modified)))))



;;;-----------------------------------------------------------------



(defvar displaying-line-numbers-p nil)

(make-variable-buffer-local 'displaying-line-numbers-p)

(defvar display-line-numbers-format-string nil)

(make-variable-buffer-local 'display-line-numbers-format-string)

(defvar display-line-numbers-first-line nil)

(make-variable-buffer-local 'display-line-numbers-first-line)

(defvar display-line-numbers-count 0)

(make-variable-buffer-local 'display-line-numbers-count)

(defvar display-line-numbers-buffer-name nil)

(make-variable-buffer-local 'display-line-numbers-buffer-name)

(defvar display-line-numbers-modified-p nil)

(make-variable-buffer-local 'display-line-numbers-modified-p)



;;;###autoload

(defun toggle-line-numbers-display (arg)

  "Display/clear line numbers in left margin of current buffer.

With prefix ARG, just number lines in current window, not all lines in

buffer."

  (interactive "P")

  (if displaying-line-numbers-p

      (turn-off-line-numbers-display)

    (turn-on-line-numbers-display arg)))



;;;###autoload

(defun turn-on-line-numbers-display (arg)

  "Display line numbers in left margin of current buffer.

With prefix ARG, just number lines in current window, not all lines in

buffer."

  (interactive "P")

  (or (eq (current-buffer) (window-buffer (selected-window)))

      (error "Current buffer, %s, is not the selected window's buffer"

             (buffer-name)))

  (let ((buffer-read-only nil)

        (point (point-marker))

        line-number

        nlines)

    (setq display-line-numbers-buffer-name buffer-file-name)

    (setq display-line-numbers-modified-p (buffer-modified-p))

    (save-restriction

      (widen)

      (save-excursion

        (setq display-line-numbers-first-line

              (if arg

                  (window-start (selected-window))

                (point-min)))

        (goto-char display-line-numbers-first-line)

        (setq line-number (1+ (count-lines (point-min) (point))))

        (if arg

            (move-to-window-line -1)

          (goto-char (point-max)))

        (beginning-of-line)

        (setq nlines (count-lines display-line-numbers-first-line (point)))

        (let ((max (+ line-number nlines)))

          (setq display-line-numbers-format-string (cond ((< max 100) "%2d ")

                                    ((< max 1000) "%3d ")

                                    ((< max 10000) "%4d ")

                                    (t "%7d "))))))

    (save-excursion

      (condition-case nil

          (progn

            (goto-char display-line-numbers-first-line)

            (setq buffer-file-name nil) ; To prevent saving with line numbers etc.

            (setq displaying-line-numbers-p t)

            (while (<= display-line-numbers-count nlines)

              (insert-before-markers

               (format display-line-numbers-format-string line-number))

              (setq line-number (1+ line-number))

              (setq display-line-numbers-count (1+ display-line-numbers-count))

              (forward-line 1))

            (when arg

              (set-window-start (selected-window) display-line-numbers-first-line))

            (goto-char point)

            (set-buffer-modified-p display-line-numbers-modified-p))

    (error

     (progn

           (goto-char display-line-numbers-first-line)

           (let ((n (1+ (- (aref display-line-numbers-format-string 1) ?0))))

             (while (> display-line-numbers-count 0)

               (setq display-line-numbers-count (1- display-line-numbers-count))

               (delete-char n)

               (forward-line 1)))

           (setq buffer-file-name display-line-numbers-buffer-name)

           (set-buffer-modified-p display-line-numbers-modified-p)

           (setq displaying-line-numbers-p nil))))))

  (let ((curr-line (count-lines (window-start) (point))))

    (when (> curr-line 0) (setq curr-line (1+ curr-line)))

    (recenter curr-line)))



;;;###autoload

(defun turn-off-line-numbers-display ()

  "Clear displayed line numbers from left margin of current buffer."

  (interactive)

  (unless (eq (current-buffer) (window-buffer (selected-window)))

    (error "Current buffer, `%s', is not the selected window's buffer"

             (buffer-name)))

  (unless displaying-line-numbers-p

    (error "Not displaying line numbers in buffer `%s'" (buffer-name)))

  (let ((buffer-read-only nil))

    (save-excursion

      (when (boundp 'display-line-numbers-buffer-name)

        (setq buffer-file-name display-line-numbers-buffer-name))

      (goto-char display-line-numbers-first-line)

      (let ((n (1+ (- (aref display-line-numbers-format-string 1) ?0))))

        (while (> display-line-numbers-count 0)

          (setq display-line-numbers-count (1- display-line-numbers-count))

          (delete-char n)

          (forward-line 1)))

      (when (boundp 'display-line-numbers-modified-p)

        (set-buffer-modified-p display-line-numbers-modified-p))

      (setq displaying-line-numbers-p nil))))





;;;;;;;;;;;;;;;;;;;;;;;



(provide 'line-num)



;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;; line-num.el ends here