Transient Prompts, LS_COLORS, and Theming

Coloring of the prompt is controlled by the `block` in `PROMPT_COMMAND` where you can write your own custom prompt. We've written a slightly fancy one that has git statuses located in the [nu_scripts repo](https://github.com/nushell/nu_scripts/blob/main/modules/prompt/oh-my.nu). ### Transient Prompt If you want a different prompt displayed for previously entered commands, you can use Nushell's transient prompt feature. This can be useful if your prompt has lots of information that is unnecessary to show for previous lines (e.g. time and Git status), since you can make it so that previous lines show with a shorter prompt. Each of the `PROMPT_*` variables has a corresponding `TRANSIENT_PROMPT_*` variable to be used for changing that segment when displaying past prompts: `TRANSIENT_PROMPT_COMMAND`, `TRANSIENT_PROMPT_COMMAND_RIGHT`, `TRANSIENT_PROMPT_INDICATOR`, `TRANSIENT_PROMPT_INDICATOR_VI_INSERT`, `TRANSIENT_PROMPT_INDICATOR_VI_NORMAL`, `TRANSIENT_PROMPT_MULTILINE_INDICATOR`. By default, the `PROMPT_*` variables are used for displaying past prompts. For example, if you want to make past prompts show up without a left prompt entirely and leave only the indicator, you can use: ```nu $env.TRANSIENT_PROMPT_COMMAND = "" ``` If you want to go back to the normal left prompt, you'll have to unset `TRANSIENT_PROMPT_COMMAND`: ```nu hide-env TRANSIENT_PROMPT_COMMAND ``` ## `LS_COLORS` Colors for the [`ls`](/commands/docs/ls.md) Command Nushell will respect and use the `LS_COLORS` environment variable setting on Mac, Linux, and Windows. This setting allows you to define the coloring of file types when you do a [`ls`](/commands/docs/ls.md). For instance, you can make directories one color, `.md` Markdown files another color, `.toml` files yet another color, etc. There are a variety of ways to color and style your file types. If `LS_COLORS` is not set, nushell will default to a built-in `LS_COLORS` setting, based on [8-bit (extended) ANSI colors](https://en.wikipedia.org/wiki/ANSI_escape_code#8-bit). ### Understanding `LS_COLORS` `LS_COLORS` contains a colon (`:`) separated list of records that map file types and file names to styling attributes (`selector=attributes`). The selector can be a file type specified like `di` for "directory identifier", or `*.nu` for files with the `.nu` file extension. The attributes are a list of semicolon (`;`) separated numbers. Note that which attributes and attribute formats are supported depends on the terminal you are using. - Style attributes like `0` normal, `1` bold, `3` italic, `5` blink, [etc](https://en.wikipedia.org/wiki/ANSI_escape_code#Select_Graphic_Rendition_parameters) - [Foreground colors](https://en.wikipedia.org/wiki/ANSI_escape_code#3-bit_and_4-bit) `30`-`37` and `90`-`97` - [Background colors](https://en.wikipedia.org/wiki/ANSI_escape_code#3-bit_and_4-bit) `40`-`47` and `100`-`107` - [RGB foreground](https://en.wikipedia.org/wiki/ANSI_escape_code#24-bit) prefixed with `38;2`, optionally followed by additional attributes - [RGB background](https://en.wikipedia.org/wiki/ANSI_escape_code#24-bit) prefixed with `48;2`, optionally followed by additional attributes For example: `$env.LS_COLORS = "di=1;34:*.nu=3;33;46"`: Bold directories, italic yellow foreground cyan background `*.nu` files `$env.LS_COLORS = "di=48;2;200;0;0;5"`: Red background blinking directories ### vivid Themes For example, you can use the third-party tool [vivid](https://github.com/sharkdp/vivid), which runs on multiple platforms, has [many themes defined](https://github.com/sharkdp/vivid/tree/master/themes), and generates a `LS_COLORS` configuration from it. After downloading and extracting the binary, you can use it with: ```nu $env.LS_COLORS = (vivid generate molokai) ``` or with an alternative theme: ```nu $env.LS_COLORS = (vivid generate ayu) ``` You can put this command into your [Nushell configuration](/book/configuration.md) for it to become the default coloring. ## Theming Theming combines all the coloring above. Here's a quick example of one we put together quickly to demonstrate the ability to theme. This is a spin on the `base16` themes that we see so widespread on the web.

This section covers how to configure transient prompts in Nushell, allowing for different prompts for previously entered commands. It explains how to use the `TRANSIENT_PROMPT_*` variables and provides examples. The section then discusses the `LS_COLORS` environment variable, which enables users to customize the coloring of file types in the `ls` command. It details the structure of `LS_COLORS` and provides examples of how to set it. It then introduces `vivid` as an alternative tool. The section concludes with an introduction to theming, which combines all the coloring options described previously.