#emacs tidbits

2005.04.20

2005-04-20T23:59:00.000-07:00

Gnus: Although Gnus' interface is more like a news reader than other mail clients, its rich features make it a popular choice for reading mail in Emacs.; You can use / o to show old messages.; Check out swish++, mairix, and other mail search engines.; http://my.gnus.org has sample configuration files.
Templates: If you want to define templates so that creating a new LaTeX file will prompt you for a template and fill it in, check out EmacsWiki: and EmacsWiki:.
Finder-by-keyword: To see a brief description of various packages included in your Emacs, use C-h p (Finder-by-keyword).
Planner: If you want to see your appointments for today, use planner-appt.el and M-x planner-appt-show-alerts.; If you want to associate tasks with more than one list, check out planner-multi.el.; planner-delicious rewrites a section of your planner page to include all of your links with a certain tag.
delicious: delicious-el supports w3m import and export, tab completion on tags, search, etc.; darcs get http://www.wjsullivan.net/darcs/delicious-el
Changing the font: In GNU Emacs, shift-left-click-and-drag to change the font temporarily.; M-x set-frame-font changes the font temporarily.; M-x customize-face RET default RET changes the font permanently.; You can also change the Emacs*font Xresource or start Emacs with the -fn switch.; Get the font string with xfontsel.
Wrapping code at 80 chars: You can use GNU indent to reformat your C++ code to fit within 80 columns. Call "indent" or "astyle" using shell-command-on-region.
ERC keywords: Use erc-keywords together with erc-match-mode to keep track of when people mention your name or other keywords you're interested in.; Check out the "minimal distraction" section in EmacsWiki:.; Add every channel to erc-track-priority-faces-only, and then modify erc-track-faces-priority-list to something like (erc-current-nick-face erc-keyword-face erc-pal-face erc-nick-msg-face erc-direct-msg-face).; lisppaste: making a channel switch from priority-keywords-only to excluded to always tracked shows off switching between channels where you want to track everything that's said (when you have free time), channels where you want to only see activity that's important (when you have little free time), and channels that you don't care about, but want to stay joined to.
TRAMP: You can configure TRAMP to back up locally by setting tramp-auto-save-directory.
Redoing complex commands: You can use C-x M-: or C-x ESC ESC to repeat a complex command. This also allows you to get the Lisp form for inclusion in your ~/.emacs or other programs.

2005.02.17

2005-02-17T23:59:00.000-08:00

Editing

Copying and pasting: Set x-select-enable-clipboard to non-nil so that you can copy and paste between Emacs and other applications in X.
Changelog e-mail address: Customize user-mail-address so that your changelog entries have the right address.
Parentheses: Highlight matching parentheses in GNU Emacs with M-x show-paren-mode.
Scrolling: To make the current line the top line in the buffer, use C-u 0 C-l (C-u 0 M-x recenter).

Lisp

More Emacs Lisp strangeness: (string= "t" t), (string= "nil" nil)
split-string: The behavior of split-string has changed when used with a non-nil second argument. It used to omit leading and trailing zero length strings. It no longer does that unless the third (new) argument OMIT-NULLS is true (this will also omit empty strings in the middle of the list). As a special kludge it has the old behavior in the single argument case. - corrected by bojohan
Printing messages: To print to the echo area without writing to the Messages buffer, bind message-log-max to nil. - corrected by bojohan

Add-ons

Planner: If you want to be reminded about appointments, you can store your appointments in Diary and then have Diary remind you. Or you can bug rsh about the upcoming planner-appt.el...
Eshell: You can disable the eshell exit message by tweaking eshell-save-history-on-exit or eshell-ask-to-save-history.
Web-browsing: w3 is a web browser written in Emacs Lisp. w3m-el is a Lisp interface to the w3m web browser. It feels faster because it uses an external process.
Presentations: Check out magicpoint for a way to make slides using simple markup.

2005.01.14

2005-01-14T23:59:00.000-08:00

Packages

Working with remote files: If you're having problems with Ange-FTP but your server supports SCP, check out TRAMP. You may want to set up SSH key-based authentication as well so that you don't have to keep entering your passphrase.
RSS: Check out the nnrss module for Gnus. G R runs gnus-group-make-rss-group. You can use it to subscribe to this feed at http://feeds.feedburner.com/emacstidbits-rss20 . W h (gnus-article-wash-html) converts entries to HTML. You can also use bloglines.com , a web-based aggregator.
RCIRC: RCIRC is another small IRC client for Emacs. It has less than 1000 lines of code. Check out the #rcirc channel.
Planner: New option planner-expand-name-default makes people who normally schedule everything at +2 very happy.
Gnus tips: G S u runs gnus-summary-sort-by-unread. Try it in the Group buffer.
TeX tips: Check out qtree.sty, which is good for Lisp-heads. mla-paper on CTAN might be useful. koma-script, too.
ERC bugs: See http://www.emacswiki.org/cgi-bin/wiki/ for instructions. Don't just discuss bugs in #emacs!
Del.icio.us: delicious-el now does some basic w3m bookmark exporting

Emacs editing stuff

Goto line: For some reason, goto-line does not have a default keybinding. Fix this by adding something like (global-set-key [(meta ?g)] 'goto-line) to your ~/.emacs.
Getting help: Do you know about M-x finder-commentary yet? It's a great addition to info, apropos, and describe-function.
Copying in XEmacs: (setq interprogram-cut-function 'own-clipboard) (setq interprogram-paste-function 'get-clipboard)
Auto Revert: If you need to fire up another Emacs instance temporarily and that instance will modify files open in your current Emacs, save everything (C-x s !), use and close the other Emacs, then toggle M-x global-auto-revert-mode twice to refresh all the files in the current Emacs session.
Character count: Pipe everything to the wc utility or use M-= (count-lines-region). tex-count-words is also neat.

Coding

Debugging Emacs Lisp: M-x toggle-debug-on-error will give you a backtrace when your program dies with an error. edebug is handy for stepping through code.
Advice: C functions calling C functions will ignore any advice.
Defining derived modes: define-derived-mode makes it very easy to write a mode that behaves like another one.

2005.01.13

2005-01-13T23:59:00.000-08:00

,commands are stuff to tell fsbot on irc.freenode.net. For example, ,w3m means /msg fsbot w3m .

External packages

w3m: a console-based Web browser with excellent Emacs support. http://w3m.sourceforge.net, http://emacs-w3m.namazu.org; Turn on images with M-x w3m-toggle-inline-images-permanently .
Emacspeak: an audio desktop environment for Emacs. You can use a free speech synthesizer like flite to get speech feedback for Emacs functions. See ,emacspeak for more details.
Transparent remote file access: You can use TRAMP to access files over SSH from your Emacs or XEmacs.
ERC doctor: Check out ,ercdoctor for code to run M-x doctor on whatever was last said on IRC.
Templates: You can use ,template packages to automatically insert text when you create a file.
Reformatting HTML: Try HTML Tidy at http://www.emacswiki.org/elisp/tidy.el or the command-line htmltidy program.
Battery support: Laptop users can keep track of their battery life with battery.el . http://sprocket.stanaway.net/~david/emacs/battery-pmac.el for Powerbooks.
Take typing breaks: typebreak encourages you to rest every so often.
Converting Mutt .alias files to BBDB: Check out ,bbdb for more information.

Editing

Distinguishing filenames in the modeline: (require 'uniquify) (setq uniquify-buffer-name-style 'forward)
Abbrev mode: If you use abbrev-mode, make sure your abbreviations are composed of word characters. Characters like ";" will not be recognized.
Clipboard in XEmacs: (setq interprogram-paste-function 'get-selection-foreign)
Goto-line keybinding: Not bound by default. M-g seems to be a popular keybinding for this.
Regexp replacement: To replace text between AAA and BBB, M-x query-replace-regexp RET \(AAA\).*\(BBB\) RET \1whatever\2. \1 and \2 save the contents of the parentheses groups in the regular expression.
Recognizing function key sequences: The function-key-map variable allows you to recognize function keys if you only have their ASCII equivalents. In the console, C-q <control-sequence> to find out what to put in this variable. For example, (define-key function-key-map "\e05D" [C-left])

Coding

Minor modes in files: Check out the Emacs info node on "File Variables" to find out more about setting local variables when a file is loaded.
Case sensitivity in commands: M-x FOO and M-x foo are different, but C-x F is translated to C-x f if the former is not bound.
Shell-scripting with Emacs: #!/path/to/CVS/emacs --script . You can use command-line-args[-left] to access arguments and kill-emacs to specify an exit code.
Advising primitives: See (info "(elisp)Advising Primitives") . It works on the Lisp level, but not on the C level.
Bitwise operations: (info "(elisp)Bitwise Operations") if you need to do funky binary operations. Don't forget that 0 != nil.
CVS Emacs bug with defcustom variables: Defcustom variables are broken as of 2004-12-27.

2005.01.12

2005-01-12T23:59:00.000-08:00

See more of the hello messages in C-h h by downloading intlfonts.
Input special characters by typing C-q followed by the character or the octal code for that character.
Want to remind yourself about modified but uncommitted files? Add something to kill-emacs-query-functions.
Tweak symbols used for console displays by setting buffer-display-table.
Automatically recognize .fpp files as Fortran with (add-to-list 'auto-mode-alist '("\\.fpp\\'" . fortran-mode))
Set your shell prompt in ~/.emacs_SHELLNAME (ex: ~/.emacs_bash).
Lots of diff modes: xxdiff, UniDiffMode, DiffMode, EmergeDiff
For autocompletion and lots of other goodies, check out cedet.
If you want Emacs started with a default height, width, and other attributes, check out default-frame-alist or ~/.Xresources .
Can http://webcleaner.sourceforge.net be used to Javascript-enable w3m?
sxemacs, a new Emacs fork, ran indent(1) over all the Emacs C code.
Issue: mixal-mode.el has problems font-locking comments when text after a command contains a *. Example: ADD 3 this * foo
Mini-emacsen: zile, jasspa-microemacs, quemacs
If your Emacs shows a black line on the first and last row, that could be visual bell.
To make Emacs 21 look more like Emacs 20, (menu-bar-mode -1) (tool-bar-mode -1) (setq scalable-fonts-allowed nil) (blink-cursor-mode -1)
Control ERC line rotation in a channel buffer with (setq erc-max-buffer-size 600000) and erc-truncate mode
Auctex shortcut for closing environments: C-c ]
To edit a dired buffer by hand and commit changes, see wdired.el.
re-builder can help you build regular expressions.
Lots of discussion about ERC prompts, front-sticky, and rear-nonsticky.
From comp.emacs: http://www.therandymon.com/papers/emacs-for-writers.pdf
Web browsers for Emacs: w3m, w3, lynx, or any of the console browsers. w3 is written in Emacs Lisp. w3m has good Emacs support.
w3m: Can't get to a self-signed authenticated site? Also, simple-wiki messes with its keybindings.
M-x toggle-truncate-lines to turn off wrapping
Recursive edit is wonderful. You can do other commands while you're in the minibuffer.

2005.01.11

2005-01-11T23:59:00.000-08:00

New bookmark integration for delicious-el: delicious-w3m-bookmark-recent
Modify backup settings by changing backup-directory-alist . fsbot: backups for more details.
To view DVI files with kdvi instead of xdvi, modify TeX-view-style and TeX-output-view-style
If you have a region, you can use rectangle commands. kill-rectangle, yank-rectangle... If you want to see rectangles, use either cua or rectanglemark.
C-u C-x = describes the current character in great detail.
Automatically identify yourself on nickserv using erc-nickserv.
fsbot: MetaKeyProblems explains how to get AltGr to work.
fsbot: nonascii has some advice on getting rid of non-ASCII characters that are forcing your text files into strange encodings.
fmakunbound or makunbound will unbind a function or variable.
M-x FOO and M-x foo are different, but C-x F and C-x f are the same unless you remind one of them.
eval-after-load is useful for running code or adding functions to hooks after loading a package. This should be declared outside the package to be loaded. Don't forget to quote the body, like this: (eval-after-load "some-file" '(progn do-stuff)) Other things that might be useful: autoload, setting variables in a config file, using a load hook.
Keep track of long Emacs Lisp defuns while programming: which-function-mode
Try pressing RET on lines in a backtrace to jump to the location, if possible. For more powerful debugging, see (info "(elisp)Edebug")
Want to fill lines with a prefix? Check out filladapt.
You can use symbol-function to find the definition of a function.
Issue: diary.el drops the starting # from "10 * #A0". For planner-cyclic tasks, use "10/* #A0 ..." instead.
Issue: perl.exe and python.exe appear to hang on eshell on ntemacs, although M-x python-mode does the right thing when the shell is invoked. Contact smitty1e for more details.

2005.01.10

2005-01-10T23:59:00.000-08:00

Contributed by p00ya

* Editing

** Capitalize a word
  M-c will Capitalize a word.

** Switching frames
  C-x 5 o will switch frames, when your window manager doesn't take
  care of it.  However, this reportedly does not work with ECB, so you
  can try windmove instead.

** using the TAB key as a literal tab or naive indent
  Use C-q TAB or M-i to prevent your major-mode from interpreting your
  tab.

* Extending

** bbdb to diary records
  To get warnings of important dates (namely, birthdays in a bbdb) in
  advance, use bbdb-birthday-diary-export to get them to diary.

** danish keyboards
  There are problems with AltGr being Meta.  This helps:
   (set-language-environment 'latin-1)
   (set-keyboard-coding-system 'iso-latin-1)
   (add-to-list 'process-environment "LOCALE=3DC")

** an interactive macro-like DWIM insertion idea
  I don't get this, and neither did others, but it seems interesting
  if somewhat misguided.  see: http://paste.lisp.org/display/4860

** removing the menu
  Use (menu-bar-mode -1) to turn off menu bars.

** Getting key definitions on funky terminals
  When your terminal won't let you type C-c C-SPC, you can just eval:
    (key-binding (kbd "C-c C-SPC"))

* Programming

** sequence-like operations
  aref and aset are for getting/setting elements of arrays, vectors,
  strings, char-tables and bool-vectors being arrays

** filtering a list
  To filter a list based on a predicate, use (delq (mapcar p list))
  where the predicate evaluates to nil to exclude an element

** fun with times
   (require 'time-date) for useful time and date utilities.
   (days-between) calculates the difference in days between two dates
   as strings.

*** age in days
    If you were born on the 31st of December in 1980, then you would
    be:

      (- (time-to-days (current-time))
	 (time-to-days (encode-time 0 0 0 31 12 1980))

    days old.

*** parsing times
   For a quick hack to parse a yyyy-mm-dd style date, try:

     (mapcar 'string-to-number
	     (split-string "1994-12-15" "-")) => (1994 12 15)

*** formatting times
   To convert (current-time) to a human readable date, use
   (format-time-string).  To turn numbers into strings, use
   (number-to-string).

** appending text to a specific buffer
   Try:

     (with-current-buffer (get-buffer "*scratch*")
       (insert-string "hi there\n"))

2005.01.09

2005-01-09T23:59:00.000-08:00

Capturing a keyboard macro: C-x ( <stuff you want to do> C-x ) M-x name-last-kbd-macro RET foo RET C-x C-f ~/.emacs RET M-x insert-kbd-macro RET foo RET C-x C-s
Insert the output of a shell command: C-u M-!
file-name-extension: get the extension of a file
(define-key minibuffer-local-completion-map (kbd "SPC") nil) - find ways to make this work for only this call of completing-read
remove-if-not is a CL function for filtering lists.
To pad columns with spaces, use negative precision in format. Ex: (format "%-10s%-10s" "aa" "bbb")
ielm: Interactively interpret Emacs Lisp expressions

2005.01.08

2005-01-08T23:59:00.000-08:00

IRC stuff

rcirc, a new IRC client for Emacs: http://www.emmet.ca/~rcyeske/rcirc .
erc-cmd-<TAB> to see the list of possible ERC commands. For example, erc-cmd-SV can be called with /sv
ERC: DCC GET works in all emacsen, DCC SEND works only in CVS Emacs- Don't worry, M-x erc-select doesn't unselect the current server.
#emacs is a great channel for asking Perl questions.

Buffers

C-x ^ and C-x } change the size of a window, as does dragging the window border with the mouse.
Use buffer-menu or ibuffer when you need to kill lots of buffers.
Kill all buffers that match "regexp": (dolist (i (buffer-list) (when (string-match "regexp" (buffer-name i)) (kill-buffer i))))
To have Emacs correctly wrap even when you resize windows, update fill-column var in window-size-change-functions. This does not refill old text, though.

Misc

Tweak your tab behavior by changing indent-tabs-mode and tab-width.
paren-mode to toggle parenthesis-checking in a buffer.
If you're having problems binding keys like M-TAB, make sure your window manager isn't using that key.
line-number-at-pos returns the current line number. what-line prints it out.
To find out where a line is relative to the start of the window, (- (line-number-at-pos (point)) (line-number-at-pos (window-start)))
next-text-property-bounds is an XEmacs function that finds a range of contiguous text with a given text property. You can do it in Emacs by building something around next-single-property-change.
Alternative stylesheet for http://emacswiki.org - http://purl.org/NET/wence/emacswiki.css
If you must run vim inside Emacs because you like Emacs' input methods, try ansi-term.
http://www.emacswiki.org/cgi-bin/wiki/ has font suggestions.

EmacsWiki

SpeedBar has tips for dealing with strange window managers.

2005.01.07

2005-01-07T07:06:00.000-08:00

Code and Usage Tips

Tips for reading Gutenberg e-books: Make your font smaller or refill all the paragraphs. To refill paragraphs, record a keyboard macro that calls fill-paragraph and forward-paragraph.
Working on documents: antiword and catdoc help with Microsoft Word documents, but LaTeX is very good for collaboration, long documents, and clean output. emacs-LaTeX-RefTeX gives you a nice environment. See also latex-preview.
To encode strings for use in URLs, you can use url-hexify-string, w3m-url-encode-string, emacs-wiki-escape-url, or similar functions.
delicious-w3m-html fetches feeds for particular users and tags.
http://www.emacswiki.org/cgi-bin/wiki/ - get a GNOME dialog box when someone talks to you on ERC.
You can use dict along with dict-gcide and other dictionaries to look up terms within Emacs.
Access the menus using your keyboard with F10, M-`, or M-x tmm-menubar .
Switching windows and buffers: C-x o, C-x b, windmove, cyclebuffer...
Need to find out when today - 25 days was? Borrow code from planner-calculate-date-from-day-offset.
erc-autoaway.el revision: http://dev.gentoo.org/~jbms/erc-autoaway-revision.patch . Requires some changes to configuration interface, though.
To be able to call functions with M-x, make them interactive. (defun myfunc () "bla" (interactive) ...)
erc-bbdb can track people based on their finger hosts.

Issues

comment-dwim appears to be missing from XEmacs.
How do you turn on global-font-lock-mode for both GNU Emacs and XEmacs? XEmacs doesn't have the global-font-lock-mode variable. Answer: Just font-lock-mode might work.
Reverting buffers to erc-mode after an accidental mode change appears to be currently impossible.
XEmacs doesn't have extended character class support, and GNU Emacs 21.3 and CVS differ in their support.
planner-diary-update-section needs to be run from pages that are open in a buffer and are recognized as planner pages.
unicode cjk characters are not supported by released GNU Emacs yet. Try the Unicode branch or (utf-translate-cjk-mode 1) in CVS Emacs.

Misc

sxemacs is a new fork of XEmacs for things the XEmacs review board won't accept. It's looking into using Xft fonts instead of core fonts and ditching Windows support because the developers don't use Windows.
The Diary/PlannerMode/Emacs combination is addictive.
The darcs repository for ljupdate is more up-to-date than the CVS repository. It's a clean rewrite with a different design.

2005.01.05, 2005.01.06

2005-01-06T19:02:00.000-08:00

Here are interesting tidbits from irc://irc.freenode.net/#emacs for 2004.01.05 to 2004.01.06.

Code

M-x column-number-mode makes Emacs show column numbers.
emms-locate is a useful way to play selected media files.
Powerful buffer switching: With either iswitchb or ido, C-x b C-s. ido seems to be better than iswitchb for multitty Emacs, and comes with CVS GNU Emacs. iswitchb is in GNU Emacs and the edit-utils package for XEmacs. If you want to stick with iswitchb fulltime, add (iswitchb-default-keybindings) to your init.el.
ess (emacs spreadsheet): set-variable set-goal-column nil for neater navigation
emms: (define-key dired-mode-map [.] 'emms-play-dired) after dired is already loaded
Editing XML: Many people recommend nxml (GNU Emacs only). xsl-mode is also useful even for other XML files. xsl-mode indentation is better than xml-mode, too. xsl-mode is in the xslide package, and in the cygwin sumo package.
If you want Python files recognized, install python-mode and (add-to-list 'auto-mode-alist (cons "\\.py\\'" 'python-mode))
Gnus: You can use B DEL to delete drafts.
Recursion in lambdas! (funcall #1=(lambda (n) (if (= n 0) 1 (* n (funcall #1# (1- n))))) 5) - result: 120. Not recommended.
Use M-x goto-line to go to the nth line.
To copy the font setting and color-theme of the old frame when you create a new frame: (defadvice make-frame (around frob-frame-parameters activate) (let ((default-frame-alist (frame-parameters))) ad-do-it))
How to get rid of all the ^Ms at the end of lines: M-% C-q C-m RET C-q RET RET . (Better solution: M-x revert-buffer-with-coding-system, dos.)
desktop can make Emacs jump to the previous position in a file when you reopen the file
Setting auto-fill in file comments: -*- mode: major; mode: auto-fill -*-, where major is the major mode you want. Note: This is Evil. Don't do it. auto-fill is a matter of personal preference.

Issues

ess toolbar variables (customization) need to be set before ess is loaded, but ess is loaded in site-start. How do you set it, then?

Misc

ljupdate darcs repository: http://edward.oconnor.cx/code/ljupdate/
ERC seems to be the most popular IRC client.
Have you checked out the Emacs LiveJournal community? http://www.livejournal.com/community/emacs/
Don't worry about losing local changes when you modify the source code of CVS Emacs. CVS does patches.
Emacs under screen: C-\ might be a good Screen escape key.
People use normal synchronization tools like rsync, unison, and CVS to sync their planner.el pages between computers.
Hook variables named -hook tend to not take arguments, while hook variables named -functions might be called with arguments.
Debian: /etc/emacs/site-start.d and /usr/share/emacs/site-lisp/debian-startup.el are responsible for lines like "Loading 00debian-vars (source)...", while /usr/lib/emacsen-common/emacs-package-install is called when the deb is being set up.