automatically read-only mode enabled after idle some time

Now add the following function to `.emacs', and then emacs can automatically toggle into read-only mode after idle some time:

;;; 128秒沉寂后自动转入只读模式
(setq timer_read-only (run-with-idle-timer 128 t 'toggle-read-only 1))

eshell

history

The ‘history’ command shows all commands kept in the history ring as numbered list. If the history ring contains eshell-history-size commands, those numbers change after every command invocation, therefore the ‘history’ command shall be applied before using the expansion mechanism with history numbers.

The n-th entry of the history ring can be applied with the ‘!n’ command. If n is negative, the entry is counted from the end of the history ring.

‘!foo’ expands to the last command beginning with foo, and ‘!?foo’ to the last command containing foo. The n-th argument of the last command beginning with foo is accessible by !foo:n.

emacs临时绑定一个elisp函数到某个键组合

(global-set-key (kbd "<f8>")
   (lambda() 
        (interactive)
        (save-buffer)
        (call-process-shell-command "latex -interact=batchmode -output-format=pdf assignment_2")
        (message "having generated pdf successfully")))

必须调用“interactive“函数。

emacs画表时指定画表符号

Characters used to recognize/draw the borders of the table can be specified with the help of the following variables:

table-cell-horizontal-chars

Contains a string. All characters in string are valid horizontal delimiters for the table. The first character of the string is used for output.

table-cell-horizontal-char

Contains the character used as the vertical delimiter. “|” by default.

table-cell-intersection-char

Contains the character that appears at the intersection of rows and columns. “+” is the default.

The following settings give interesting results. They use utf-8 characters to draw continuous lines for the border of the table. Arguably, your font should support these character to display the desired effect.

(setq table-cell-horizontal-chars "\u2501")
(setq table-cell-vertical-char ?\u2503)
(setq table-cell-intersection-char ?\u254B)

Use the Third Part elisp Package

Put some .el file to womewhere like `~/.elisp', and add .emacs with expressions like the following two lines:

(add-to-list 'load-path "~/.elisp")
(require 'foo)

Alternate Default Debian Editor

The default editor in Debian is nano. User may change that:

$ update-alternatives --config editor

emacs cheat sheet

1. Bookmark:
   

   C-x r m
   C-x r b

2. Uppercase initial:
   

   upcase-initials-region

3. 搜索当前位置的单词：
   

   C-s C-w

4. 搜索性质的高亮：
   

   C-s C-w C-w ...

5. 复制矩形块区域（即列选择）
   

   C-x r r register_name
   C-x r i register_name

6. 复制区域
   

   C-x r s register_name

   C-x r i register_name

7. 删除矩形区

   M-x delete-rectangle

8. 保存位置及返回（非书签方式）
   

   C-x r SPC register_name

   C-x r j register_name

9. see manual for perfectly printing
10. 高亮：
    

    C-x w h

    C-x w r

11. Indent multiple lines (within a region):
    

    C-M-\

12. Indent multiple lines (within a parenthesized programming expression block):
    

    C-M-q

13. Resize current window (not the frame):
    

    C-x ^ # to make the current windows taller
    C-x { # to make it wider

14. eshell mode operations:
    

    M-p # Fetch the next earlier old shell command.
    M-n # Fetch the next later old shell command.
    M-r regexp RET # Search backwards for old shell commands that match regexp.
    M-s regexp RET # Search forwards for old shell commands that match regexp.
    C-c C-x # Fetch the next subsequent command from the history.

15. Reload file (which actually is a trick):
    

    C-x C-v RET

16. Kill job in eshell mode:
    

    C-c C-k

17. Validate XML:
    

    C-c C-v

    Maybe, an XML parser is required:
    

    $ aptitude install sp

18. Show key-binding and help of current mode:
    

    C-h m

19. Transpose text:
    

    C-t # 2 characters
    M-t # 2 words
    C-x C-t # 2 lines

20. Temparorily key-binding to a script
    

    M-x local-set-key RET key RET command RET

21. Highliting parenthesis
    

    M-x show-paren-mode

22. Yanking to mini-buffer as searching
    

    C-s M-y

23. Toggling buffer with read-only
    

    C-x C-q

24. 折行：
    

    M-q
    C-x f # set column width
    M-x fill-region
    M-x fill-region-as-paragraph
    M-s # center a line
    M-x auto-fill-mode # automatic mode
    M-x set-fill-column # adjust column number for auto-fill-mode

25. goto-line
    

    M-g g

26. Show column number:
    

    M-x column-number-mode

27. Completion:
    

    M-/