Select one of:
(set 'variable value) (setq variable value) (defvar variable value "documentation")
or file local:
# Local variables: # variable: value # End:
(apropos-value "PATT") (apropos-variable "PATT") (apropos-function "PATT") (apropos-library "PATT") (apropos-documentation "PATT")
Type M-: than lisp expression than type RET.
Or in any buffer place point at the end of lisp expression and type C-x C-e.
Or invoke elisp "shell" by M-x ielm.
See value of variable load-history (by C-h v load-history RET):
(symbol-file 'scheme 'provide) ; Who provide feature. (symbol-file 'nxml-mode-hook 'defvar) ; Where variable defined. (symbol-file 'message-send 'defun) ; Where function defined. (symbol-file 'scheme) ; Look for symbol despite its type. load-history (locate-library "gnus.el") (find-lisp-object-file-name 'c-mode (symbol-function 'c-mode))
Execute M-x edebug-defun (also on C-u C-M-x) on defun in source code to enable debugging for desired function. When next time this function invoked you entered to its debugging (jumped to its source code).
To start debug execute code which used debugged function.
You can disable edebug on a function by evaluating the function again using C-M-x.
Use M-x debug-on-entry and M-x cancel-debug-on-entry to control which functions will enter the debugger when called. Next time that function loaded in debug-mode.
You can use (debug) in your function to automatically enter to debugger.
You can use (backtrace) to print a trace of Lisp function.
When your ini has a bug, or when you load external files that cause errors, the bug is often hard to find, because the Emacs Lisp reader does not know about line numbers and files - it just knows an error happened, and that's it.
Try run Emacs with --debug-init to see backtrace.
Remember Emacs elisp interpreter single threaded. To interrupt long running command press C-g. Sometime it should be typed several times.
On toggle-debug-on-quit or M-x debug-on-quit RET on C-g Emacs enter to debug mode.
First run Emacs without loading anything:
$ emacs --no-init-file --no-site-file
or more shortly (as -Q imply -q, --no-site-file, and --no-splash together):
$ emacs -Q
If bug not reproduced bug lies in ini files!
Select half of the file in a region, and M-x eval-region. Depending on whether that causes the error or not, split this half or the other half again, and repeat.
Add (error No error until here) in the middle of your file. If you get the error No error until here when reloading the file, move the expression towards the back of the file, otherwise towards the front of the file.
Set in source:
(setq debug-on-error t)
or invoke Emacs like:
$ emacs --debug-init
where --debug-init binds debug-on-error to t while loading the init file, and bypasses the condition-case which normally catches errors in the init file.
Before byte compiling file execute:
(setq byte-compile-generate-call-tree t)
edebug allow save execution statistic on per line basis. As usual evaluate C-u M-S-x (or M-x edebug-defun) on top lovel functional form. Call code that uses examined function. On entry to edebug type c (edebug-continue-mode). After finishing evaluation place cursor to examined function form and evaluate M-x edebug-display-freq-count. Function be annotated with evaluation counts per line.
(benchmark-run 1 (revert-buffer)) (benchmark-run-compiled 1 (hi-lock-face-phrase-buffer "hello" 'hi-yellow))
Enter a prefix for M-x elp-instrument-package, perform action and see result by M-x elp-results. To perform new measurement don't forget to run M-x elp-reset-all.
(checkdoc) (byte-compile-file (buffer-file-name)) (package-buffer-info)
Select region, type C-u M-| sort -u RET.
With transient-mark-mode and delete-selection-mode enabled: select region, type M-| sort -u RET to replace selection with sorted and uniquified lines.
emacs-major-version emacs-minor-version window-system - ``nil`` if in terminal, ``w32`` if native Windows build, ``x`` if under X Window window-system-version - for windows only window-size-fixed operating-system-release - release of the operating system Emacs is running on system-configuration - like configuration triplet: cpu-manufacturer-os system-configuration-options system-name - host name of the machine you are running on system-time-locale system-type - indicating the type of operating system you are using: ``gnu`` (GNU Hurd), ``gnu/linux``, ``gnu/kfreebsd``, ``berkeley-unix`` for (FreeBSD), ``darwin`` (GNU-Darwin, Mac OS X), ``ms-dos``, ``windows-nt``, ``cygwin`` system-uses-terminfo dynamic-library-alist or deprecated image-library-alist - alist of image types vs external libraries needed to display them
and check functions:
(fboundp ...) - return t if SYMBOL's function definition is not void (featurep ...) - returns t if FEATURE is present in this Emacs (display-graphic-p) - return non-nil if DISPLAY is a graphic display; graphical displays are those which are capable of displaying several frames and several different fonts at once (display-multi-font-p) - same as ``display-graphic-p`` (display-multi-frame-p) - same as ``display-graphic-p`` (display-color-p) - return t if DISPLAY supports color (display-images-p) - return non-nil if DISPLAY can display images (display-grayscale-p) - return non-nil if frames on DISPLAY can display shades of gray (display-mouse-p) - return non-nil if DISPLAY has a mouse available (display-popup-menus-p) - return non-nil if popup menus are supported on DISPLAY (display-selections-p) - return non-nil if DISPLAY supports selections
Run those checks as below:
(when window-system ...) (when (eq window-system 'x) ...) (when (>= emacs-major-version 22) ...) (when (fboundp '...) ...) (when (featurep '...) ...)
Get MSYS for POSIX shell and utilities . Get MinGW for GCC. Get Gnuwin32 for jpeg, ungif, tiff, xpm, png, zlib libraries.
$ cmd $ cd emacs\nt $ configure.bat --prefix %INST_ROOT% --with-gcc --cflags -I%GNUWIN32_ROOT%/include --ldflags -L%GNUWIN32_ROOT%/lib --ldflags -lregex $ make bootstrap $ make info $ make install
;;; <file-name>.el --- <one-line-description> ;; Copyright (C) <years> <person> ;; Author: <person> <mail> ;; Maintainer: <person> <mail> ;; Created: <date> ;; Version: <version> ;; Keywords: <look for ``finder-by-keyword`` output, separate by comma> ;; URL: <file-location> ;;; Commentary: <bla-bla-bla> ;;; Code: <lisp-code> ;;; <file-name> ends here
$ apt-get install emacs
source-directory data-directory doc-directory exec-directory invocation-directory trash-directory tutorial-directory user-emacs-directory widget-image-directory
hanoi hanoi-unix life pong tetris gomoku
(setq longlines-show-hard-newlines t) (setq longlines-wrap-follows-window-size t) (longlines-mode 1)
(message "%S" '(a b 123 "hello" 'set)) (pp '(a b 123 "hello" 'set)) (prin1-to-string '(1 2)) (symbol-name 'f) (symbol-value 'f) (symbol-function 'f) (symbol-plist 'f) (local-variable-p var buffer)
-*- mode: grep; mode: auto-revert-tail; default-directory: "~/devel/proj" -*-
XSLT-process is a minor mode for GNU Emacs/XEmacs which transforms it into a powerful editor with XSLT processing and debugging capabilities.
The mode currently supports two Java XSLT processors:
Put first line to your log file, you must replace default-directory to dir where you build program:
-*- mode: compilation-minor; mode: auto-revert-tail; default-directory: "~/devel/proj" -*-
Program must use one of supported by compilation-minor-mode (see compilation-error-regexp-alist), like:
printf(__FILE__ ":%d: %s\n", __LINE__, msg); /* msg - user defined string */
or in second form (in this case line number included in format string, so easy searchable in debugger):
#define NUM2STR(x) STR(x) #define STR(x) #x printf(__FILE__ ":" NUM2STR(__LINE__) ": %s\n", msg);
Or some faster use grep-mode, but you restricted with GNU like error format:
-*- mode: grep; mode: auto-revert-tail; default-directory: "~/devel/proj" -*-
Get main development sources:
$ bzr init-repo --2a emacs $ cd emacs $ bzr branch http://bzr.savannah.gnu.org/r/emacs/trunk trunk $ cd trunk $ bzr bind http://bzr.savannah.gnu.org/r/emacs/trunk
To update with latest changes:
$ cd emacs/trunk $ bzr update
ELPA goal is to make it simple to install, use, and upgrade Emacs Lisp packages.
Currently (2011-02-15) available such sources:
(setq package-archives '(("ELPA" . "http://tromey.com/elpa/") ("gnu" . "http://elpa.gnu.org/packages/") ("marmalade" . "http://marmalade-repo.org/packages/") ))
flush-lines keep-lines align-regexp C-x C-o M-PageUp/M-PageDown command-history M-= C-x l locate-library find-library features load-history