If you are lucky, your sysadmins have already arranged everything so that Emacs automatically goes into Octave mode whenever you visit an Octave code file as characterized by its extension .m. If not, proceed as follows.
(autoload 'octave-mode "octave-mod" nil t) (setq auto-mode-alist (cons '("\\.m$" . octave-mode) auto-mode-alist))
(add-hook 'octave-mode-hook (lambda () (abbrev-mode 1) (auto-fill-mode 1) (if (eq window-system 'x) (font-lock-mode 1))))
See the Emacs manual for more information about how to customize Font-lock mode.
In Octave mode, the following special Emacs commands can be used in addition to the standard Emacs commands.
octave-reindent-then-newline-and-indent). An abbrev before point is expanded if
nil, reindent the current line. If
nil, automagically insert a newline and indent the new line.
octave-abbrev-start). If Abbrev mode is turned on, typing `C-h or `? lists all abbrevs. Any other key combination is executed normally. Note that all Octave abbrevs start with a grave accent.
octave-beginning-of-defun). With prefix argument N, do it that many times if N is positive; otherwise, move forward to the N-th following beginning of a function.
octave-end-of-defun). With prefix argument N, do it that many times if N is positive; otherwise, move back to the N-th preceding end of a function.
octave-indent-for-comment). Point is left after the start of the comment which is properly aligned.
octave-comment-start) at the beginning of every line in the region (
octave-comment-region). With just C-u prefix argument, uncomment each line in the region. A numeric prefix argument N means use N comment characters.
octave-previous-code-line). With numeric prefix argument N, move that many code lines backward (forward if N is negative).
octave-next-code-line). With numeric prefix argument N, move that many code lines forward (backward if N is negative).
octave-beginning-of-line). If point is in an empty or comment line, simply go to its beginning; otherwise, move backwards to the beginning of the first code line which is not inside a continuation statement, i.e., which does not follow a code line ending in ‘...’ or ‘\’, or is inside an open parenthesis list.
octave-end-of-line). If point is in a code line, move forward to the end of the first Octave code line which does not end in ‘...’ or ‘\’ or is inside an open parenthesis list. Otherwise, simply go to the end of the current line.
octave-forward-block). With numeric prefix argument N, move forward across n such blocks (backward if N is negative).
octave-backward-block). With numeric prefix argument N, move backward across N such blocks (forward if N is negative).
octave-down-block). With numeric prefix argument, do it that many times; a negative argument means move backward, but still go down one level.
octave-backward-up-block). With numeric prefix argument, do it that many times; a negative argument means move forward, but still to a less deep spot.
octave-mark-block). The block marked is the one that contains point or follows point.
octave-close-block). An error is signaled if no block to close is found.
octave-help). If used interactively, the entry is prompted for with completion. If multiple matches are found, one can cycle through them using the standard ‘,’ (
Info-index-next) command of the Info reader.
octave-help-files is a list of files to search
through and defaults to
'("octave"). If there is also an Octave
Local Guide with corresponding info file, say, octave-LG, you can
octave-help search both files by
(setq octave-help-files '("octave" "octave-LG"))
in one of your Emacs startup files.
A common problem is that the <RET> key does not indent the line to where the new text should go after inserting the newline. This is because the standard Emacs convention is that <RET> (aka C-m) just adds a newline, whereas <LFD> (aka C-j) adds a newline and indents it. This is particularly inconvenient for users with keyboards which do not have a special <LFD> key at all; in such cases, it is typically more convenient to use <RET> as the <LFD> key (rather than typing C-j).
You can make <RET> do this by adding
(define-key octave-mode-map "\C-m" 'octave-reindent-then-newline-and-indent)
to one of your Emacs startup files. Another, more generally applicable solution is
(defun RET-behaves-as-LFD () (let ((x (key-binding "\C-j"))) (local-set-key "\C-m" x))) (add-hook 'octave-mode-hook 'RET-behaves-as-LFD)
(this works for all modes by adding to the startup hooks, without having
to know the particular binding of <RET> in that mode!). Similar
considerations apply for using <M-RET> as <M-LFD>. As Barry
A. Warsaw firstname.lastname@example.org says in the documentation for his
cc-mode, “This is a very common question.
:-) If you want
this to be the default behavior, don't lobby me, lobby RMS!”
The following variables can be used to customize Octave mode.
nilmeans auto-indent the current line after a semicolon or space. Default is
nilmeans auto-insert a newline and indent after semicolons are typed. The default value is
nilmeans show matching begin of block when inserting a space, newline or ‘;’ after an else or end keyword. Default is
t. This is an extremely useful feature for automatically verifying that the keywords match—if they don't, an error message is displayed.
t(default), a startup message is displayed when Octave mode is called.
If Font Lock mode is enabled, Octave mode will display
There is also rudimentary support for Imenu (currently, function names can be indexed).
You can generate TAGS files for Emacs from Octave .m files using
the shell script
octave-tags that is installed alongside your copy of
Customization of Octave mode can be performed by modification of the
octave-mode-hook. If the value of this variable is
nil, turning on Octave mode calls its value.
If you discover a problem with Octave mode, you can conveniently send a
bug report using C-c C-b (
automatically sets up a mail buffer with version information already
added. You just need to add a description of the problem, including a
reproducible test case and send the message.