rainbowpath 🌈

rainbowpath is a program for making paths pretty. It can be used to make pretty shell prompts:

rainbowpath formats supplied path by coloring each path component with a color selected from a palette. By default, colors for path components are selected based on the order they appear in the palette. If no palette is supplied a default one will be used. When invoked without a path rainbowpath displays the current working directory.

Installation

Statically linked release binaries are available on GitHub releases page. These should work on most modern Linux systems. For Arch Linux, rainbowpath is also available on AUR.

Building

./autogen.sh
./configure
make

Usage

Usage: rainbowpath [-p PALETTE] [-s PALETTE] [-S SEPARATOR] [-m METHOD]
                   [-M METHOD] [-o INDEX STYLE] [-O INDEX STYLE]
                   [-l] [-c] [-n] [-b] [-h] [-v] [PATH]

Color path components using a palette.

Options:
  -p, --palette PALETTE                 Semicolon separated list of styles for
                                        path components
  -s, --separator-palette PALETTE       Semicolon separated list of styles for
                                        path separators.
  -S, --separator SEPARATOR             String used to separate path components
                                        in the output (defaults to '/')
  -m, --method METHOD                   Method for selecting styles from palette.
                                        One of sequential, hash, random
                                        (defaults to sequential).
  -M, --separator-method METHOD         Method for selecting styles from separator
                                        palette. One of sequential, hash, random
                                        (defaults to sequential).
  -o, --override INDEX STYLE            Override style at the given index. This option
                                        can appear multiple times.
  -O, --separator-override INDEX STYLE  Override separator style at the given index.
                                        This option can appear multiple times.
  -l, --strip-leading                   Do not display leading path separator
  -c, --compact                         Replace home directory path prefix with ~
  -n, --newline                         Do not append newline
  -b, --bash                            Escape control codes for use in Bash prompts
  -h, --help                            Display this help
  -v, --version                         Display version information

Use in a Bash prompt

In Bash, what appears in the shell prompt can be controlled using the PS1 variable. In addition, PROMPT_COMMAND variable can be used to execute commands before the prompt is displayed. This mechanism can be used to dynamically modify the prompt using external commands. For example, to include rainbowpath output into the shell prompt, we could define the following function:

function reset-prompt {
  PS1="\u@\h $(rainbowpath -b) \$ "
}

PROMPT_COMMAND=reset-prompt

With this setup, rainbowpath will be executed every time prompt is about to be displayed and the output included into the prompt string.

Styles

Styles specify how path components should look. --palette and --separator-palette options accept styles as arguments. Style consists of a list of properties separated by commas. The possible properties are:

Property	Description
fg=COLOR	Set text color to COLOR
bg=COLOR	Set background color to COLOR
bold	Bold font
dim	Dim color
underlined	Underlined text
blink	Blinking text

Where COLOR is an integer between 0 and 255 or one of: black, red, green, yellow, blue, magenta, cyan, white.

For example, the following invocation will display the path of the current working directory altering styles of path components between underlined green text and bold yellow text on magenta background:

rainbowpath --palette 'fg=green,underlined;fg=yellow,bg=magenta,bold'

Style Overrides

--override and --separator-override options make it possible to selectively override the style of a path component at the given index.

For example, the following command prints all the directory components of the path in blue, except the first one (index 0 "this") which will be printed in yellow.

rainbowpath -p 'fg=blue' -o 0 'fg=yellow' '/this/is/an/example/'

Component indices can also be negative, in which case they start at the end of the list of path components. For example, the following command will print "example" in yellow.

rainbowpath -p 'fg=blue' -o -1 'fg=yellow' '/this/is/an/example/'

Override styles are merged with the base style from the palette. For example, the following command will display example in bold blue font.

rainbowpath -p 'fg=blue' -o -1 'bold' '/this/is/an/example/'

Override styles are also able to revert style properties set by the base style. This can be achieved by prefixing the property name with a !.

For example, the following command will print all path components in bold yellow font, except the last one which will be printed in the regular font:

rainbowpath -p 'fg=yellow,bold' -o -1 '!fg,!bold' '/this/is/an/example/'

Configuration Files

Configuration files can also be used to specify how paths should be displayed. The program looks for configuration from the following locations in order:

1. ~/.rainbowpath.conf
2. $XDG_CONFIG_HOME/.config/rainbowpath/rainbowpath.conf
3. From rainbowpath/rainbowpath.conf under each directory mentioned in $XDG_CONFIG_DIRS environment variable.
4. /etc/xdg/rainbowpath/rainbowpath.conf

The configuration consists of key-value pairs where the keys correspond to the program's long-form command-line options. Values can be either strings or booleans. String values should be enclosed in double quotes ("). Within a string value, a backslash (\) can be used as an escape character. The following character escape sequences are supported: \\, \", \n, \t, \r, \f, and \v. Boolean values are expressed with true and false. Hash (#) character in the beginning of a line starts a line comment. Key-value pairs cannot span multiple lines.

The following is an example of a configuration file:

method = "sequential"
palette = "fg=1; fg=3; fg=2; fg=6; fg=4; fg=5"
separator-palette = "fg=7, dim"
compact = true

# Override the style for the last component of the path.
override[-1] = "bold"

Style override indices can be specified inside brackets ([, ]) directly following the name of the option.