fchandur / nanorc

Improved syntax highlighting definitions for GNU nano

nanorc

Improved syntax highlighting definitions for GNU nano.

Description

The syntax highlighting definitions that come bundled with nano are of pretty poor quality. This is an attempt at providing a good set of accurate syntax definitions to replace and expand the defaults.

Screenshots:

Editing HTML:

Editing C:

Installation

Use make to install to ~/.nanorc.

If your terminal text color isn't black, you'll need to specify it when installing, using make TEXT=white, where white is one of the following valid color names:

red, green, yellow, blue, magenta, cyan, white

After installation, use nano examples/* to test if everything is working properly. If some or all of the files aren't highlighted properly, see the "Compatibility" section below.

Customization

Key Bindings

main.nanorc contains settings and key bindings. It can be safely deleted or changed according to preference. The default bindings try to stay close to common GUI conventions where possible (e.g. Ctrl+S for save, Ctrl+O for open).

Note: key bindings are automatically disabled when using nano versions earlier than 2.2 (see the "Compatibility" section below).

Warnings

By default, tab characters will be highlighted with a red background except when editing Makefiles. To turn this off, remove the second line from mixins/lint.nanorc and run make again.

Theming System

All *.nanorc files are passed through mixins.sed and theme.sed before installation. These scripts allow rules to be specified in terms of token names or mixins, instead of hard-coded colors.

For example, the following named rule:

TYPE: "int|bool|string"

becomes:

color green "int|bool|string"

and the following "mixin":

+BOOLEAN

becomes:

color brightcyan "\<(true|false)\>"

This system helps to keep colors uniform across different languages and also to keep the definitions clear and maintainable, which is something that becomes quite awkward using only plain nanorc files.

Note: if ~/.nanotheme exists it will be used as a custom theme, in place of theme.sed. A custom theme may also be specified by installing with make THEME=your-custom-theme.sed. Themes must be valid sed scripts, defining all color codes found in theme.sed in order to work correctly.

Compatibility

Varying support for nanorc features

The build process will automatically remove any nanorc commands that it detects to be unsupported by the installed version of nano. It will do this at the feature level where possible (e.g. undo/redo support) or otherwise make a best guess based on the version number.

Some features can be disabled at compile-time, even if theoretically "supported" by a given version, so in rare cases you my have to remove some lines manually (usually the ones in main.nanorc).

Interaction with /etc/nanorc on Debian/Ubuntu/Arch/...

If syntax highlighting fails, try removing any include or syntax lines from /etc/nanorc. There appears to be a bug in older versions of nano that causes highlighting to fail when /etc/nanorc and ~/.nanorc both exist and contain active syntax rules.

Regular expression workaround on OS X and *BSD

In order to reliably highlight keywords, this projects makes heavy use of the GNU regex word boundary extensions (\< and \>). BSD implementations also have these extensions but use a different, incompatible syntax ([[:<:]] and [[:>:]]). Since version 2.1.5, nano can automatically translate the GNU syntax to BSD syntax at run-time, but for the benefit of people running a pre-2.1.5 version of nano on OS X or *BSD, the ~/.nanorc file itself can be translated by installing with make BSDREGEX=1.