Kate

Kate is a multi-document, multi-view text editor for KDE. Very well adapted to octave. Features syntax highlighting, embedded terminal, and much more.

Syntax highlighting

Either Matlab or Octave syntax highlighting for m-file can be chosen in

Tools/Mode/Scientific menu

The default for *.m files can be defined to be octave by going to

Settings/Configure kate/Editor Component/"Open/Save"/Modes & filetypes

and setting Priority 0 for Filetype : Scientific/Matlab and Priority 1 for Filetype : Scientific/Octave (the important is that it is higher than the Matlab one)

Comment/uncomment

Kate can comment/uncomment several lines of code at the same time. Simply select the lines and press Ctr+D to comment and Shift+Ctr+D to uncomment.

For the current (april 2012) default (octave.xml version 1.01), the added comment start at the beginning of the line.

In order to have the # to begin like the indented text, just patch /usr/share/kde4/apps/katepart/syntax/octave.xml. First save the following file in /tmp for instance

File: kate_highlight_octave.xml.patch

--- /usr/share/kde4/apps/katepart/syntax/octave.xml.orig        2012-04-18 14:21:07.428924481 +0200
+++ /usr/share/kde4/apps/katepart/syntax/octave.xml     2012-04-18 14:29:38.699954596 +0200
@@ -2209,11 +2209,11 @@
 
   <general>
     <comments>
-      <comment name="singleLine" start="%" />
-      <comment name="singleLine" start="#" />
+      <comment name="singleLine" start="% "  position="afterwhitespace"/>
+      <comment name="singleLine" start="# "  position="afterwhitespace"/>,
     </comments>
     <keywords casesensitive="1"/>
   </general>
 
 </language>
-<!-- kate: space-indent on; indent-width 2; replace-tabs on; -->
+<!-- kate: space-indent on; indent-width 4; replace-tabs on; -->

The last change is not relevant for the comments.

Quit kate, then, as root, cd /usr/share/kde4/apps/katepart/syntax/ && patch -p7 --backup < /tmp/kate_highlight_octave.xml.patch