Lib.rs

Usage

vtcol knows two ways of loading a color scheme: Either by picking the definitions for a set of predefined schemes or by loading it from a definition file. The latter accepts input in the format supported by setcolors. NB not much effort has been put into ensuring compliance so YMMV. Check the subdirectory ./schemes in the vtcol tree for examples.

Three color schemes are predefined:

• default the default color scheme of the Linux console.
• solarized the Solarized color scheme, dark version.
• solarized_light the Solarized color scheme, light version.

Invoke vtcol with the --scheme option specifying the scheme of your choice:

vtcol --scheme solarized_light

In order to view the available schemes, use the --list option. Should the scheme specified not resolve to one of the predefined ones, vtcol will fall back to interpreting the name as that of a file. Likewise, loading a scheme directly from a definition file is accomplished by specifying the --file argument.

vtcol --file ./schemes/solarized

Instead of an actual scheme or file name, these parameters accept - as an argument in order to read from stdin.

Also, in order to view a scheme’s definition, for instance in order to verify that vtcol parses it correctly, specify the --dump option.

vtcol --dump default
vtcol --dump ./schemes/solarized

This will print the list of color definitions as dictated by the scheme; if the specified name does not resolve to a pre-defined scheme it will be interpreted as a file name instead.

Building

The vtcol repository aims at compliance with the standard Rust toolchain. Consequently, the project is packaged using Cargo. In order to compile a binary, run

cargo build

In the project root. This should get you a vtcol binary.

Background

The default palette that comes with a Linux terminal was inherited from a long history of virtual console implementations. The colors assigned are chosen for totally valid pragmatic reasons. However, the palette may not harmonize with everybody’s taste. Unfortunately, the console can’t be themed easily: One needs to invoke a special ioctl(2) with the colors prepared in binary form in order for the kernel to switch the palette.

vtcol attempts at facilitating the themability of the console by means of a simple plain text input format. The very popular themes from the Solarized family are included as predefined palettes; the same is true of the Linux default palette, so they can be conveniently restored when experimenting.

An implementation in C which vtcols draws much inspiration from is available in the setcolors utility. vtcols itself is implemented in Rust instead; a public repository is available on Github. The author uses the original setcolors a lot, primarily inside his custom initramfs. The primary motivations of writing vtcols stems from curiosity as to how the same goal might be achieved using more modern tools.

About

vtcols was written mostly during day-long train rides between Tübingen and Dresden, so expect the commit history to exhibit a certain lack of continuity. Its author is Philipp Gesang; see the Bitbucket (author-bb) and Github (author-gh) pages.

The vtcol source code is available from the canonical repository.

vtcol is redistributable under the terms of the GNU General Public License version 3 (exactly). The full text of the license is contained in the file COPYING in the root of the repository. Email the author if you wish to use it under a different license, there’s a non-zero chance that you might convince me.

Patches or suggestions welcome.