Trueline: Bash Powerline Style Prompt with True Color Support

Trueline is a fast and extensible Powerlinestyle bash prompt with true color (24-bit) and fancy glyph support.

The pure Bash code implementation and overall features are modelled after the excellentPureline command prompt. However Trueline alsoadds the ability to use RGB color codes, expands icon/glyph usage across prompt segments(inspired by Powerlevel9k), simplifiesconfiguration and, among other goodies, shows the current input mode (when in vi-mode).

Installation

Download the trueline.sh script in this repo and source it from within your .bashrcfile:

$> git clone https://github.com/petobens/trueline ~/trueline
$> echo 'source ~/trueline/trueline.sh' >> ~/.bashrc

or alternatively

$> wget https://raw.githubusercontent.com/petobens/trueline/master/trueline.sh -P ~/
$> echo 'source ~/trueline.sh' >> ~/.bashrc

If you use a font that supports "Powerline" glyphs, such as those included in thewonderful Nerd Fonts project, then the promptshould render properly and no further configuration is necessary (as long as you like thedefault settings shown in the image above).

Customization

Customizing and extending the prompt is easy and there are several segment optionsavailable to do so.

All settings go inside your .bashrc and must be defined before actually sourcing thetrueline.sh file (otherwise default settings will be used). To see how this works let'sstart with a simple configuration example:

declare -A TRUELINE_COLORS=(
    [light_blue]='75;161;207'
    [grey]='99;99;100'
    [pink]='199;88;157'
)

declare -a TRUELINE_SEGMENTS=(
    'working_dir,light_blue,black,normal'
    'git,grey,black,normal'
    'time,white,black,normal'
    'newline,pink,black,bold'
)

declare -A TRUELINE_SYMBOLS=(
    [git_modified]='*'
    [git_github]=''
    [segment_separator]=''
    [working_dir_folder]='...'
    [working_dir_separator]='/'
    [working_dir_home]='~'
    [newline]='❯'
    [clock]='��'
)

TRUELINE_GIT_SHOW_STATUS_NUMBERS=false
TRUELINE_GIT_MODIFIED_COLOR='grey'
TRUELINE_WORKING_DIR_SPACE_BETWEEN_PATH_SEPARATOR=false

_trueline_time_segment() {
    local prompt_time="${TRUELINE_SYMBOLS[clock]} \t"
    if [[ -n "$prompt_time" ]]; then
        local fg_color="$1"
        local bg_color="$2"
        local font_style="$3"
        local segment="$(_trueline_separator)"
        segment+="$(_trueline_content "$fg_color" "$bg_color" "$font_style" " $prompt_time ")"
        PS1+="$segment"
        _trueline_record_colors "$fg_color" "$bg_color" "$font_style"
    fi
}

source ~/trueline/trueline.sh

which generates the following prompt (that essentially replicates the minimal ZSHPure prompt):

You can see in the config above that there are basically 5 different/relevant settings:colors, segments, symbols, options and extensions. Let's break each of these down.

Colors

Colors are defined by means of an associative array named TRUELINE_COLORS. The keys ofthis array are color names and the values RGB color codes:

declare -A TRUELINE_COLORS=(
    [color_name]='red;green;blue'
)

Default colors are loosely based on Atom's One Darktheme and given by:

declare -A TRUELINE_COLORS=(
    [black]='36;39;46'
    [cursor_grey]='40;44;52'
    [green]='152;195;121'
    [grey]='171;178;191'
    [light_blue]='97;175;239'
    [mono]='130;137;151'
    [orange]='209;154;102'
    [purple]='198;120;221'
    [red]='224;108;117'
    [special_grey]='59;64;72'
    [white]='208;208;208'
)

Any TRUELINE_COLORS array defined in the bashrc file prior to sourcing the Truelinescript will actually update the default array above (in the sense that it will overwriteexisting keys and add non-existing ones). This basically means that default colors canalways be used and the array only needs to be defined when new extra colors are trulyneeded.

Note: you can define any color name you want except for default_bg which is used byTrueline to obtain the default terminal background color.

Segments

Prompt segments are defined in an ordered array called TRUELINE_SEGMENTS that has thefollowing structure:

declare -a TRUELINE_SEGMENTS=(
    'segment_name,segment_fg_color,segment_bg_color,font_style'
)

where the segment foreground and background color names are keys of the TRUELINE_COLORSarray and the font style is either bold, dim, italic, normal or underlined. Theorder of the elements in the array define the order in which each segment is rendered inthe prompt.

Trueline offers the following segments (status indicates whether they are enabled/renderedby default):

but more segments can be easily added (see Extensions).

To enable the newline segment one could use the following config:

declare -a TRUELINE_SEGMENTS=(
    'working_dir,mono,cursor_grey,normal'
    'git,grey,special_grey,normal'
    'newline,black,orange,bold'
)

which results in:

Symbols

Symbols (i.e icons/glyphs) are defined through an associative array namedTRUELINE_SYMBOLS where each entry key is a (predefined) segment symbol name and thevalue is the actual symbol/icon:

declare -A TRUELINE_SYMBOLS=(
    [segment_symbol_name]='|' # actual symbol
)

The following table shows the current predefined symbol names along with their defaultvalues (i.e either the actual glyph or the corresponding nerd-font unicode code):

As with TRUELINE_COLORS, any TRUELINE_SYMBOLS array defined in the bashrc file priorto sourcing the Trueline script will actually update the array with the default symbolsshown above (thus such array needs to be defined only when overriding some icon or addingnew ones).

Options

Most Trueline settings are controlled with the 3 structures defined above. HoweverTrueline also defines a series of variables that control some extra options. In particularwe can distinguish between intra-segment and external options. These, along with theirdefault values, are defined as follows:

Intra-segment

The next segments have (sub)settings of their own:

• git:
  • TRUELINE_GIT_SHOW_STATUS_NUMBERS=true: boolean variable that determineswhether to show (or not) the actual number of modified files and commitsbehind/ahead next to the corresponding modified-behind/ahead status symbol.
  • TRUELINE_GIT_MODIFIED_COLOR='red': foreground color for symbol and number ofmodified files.
  • TRUELINE_GIT_BEHIND_AHEAD_COLOR='purple': foreground color for symbol andnumber of commits behind/ahead.
• user:
  • TRUELINE_USER_ROOT_COLORS=('black' 'red'): root user foreground andbackground colors.
  • TRUELINE_USER_SHOW_IP_SSH=false: boolean variable that determines whether toshow the ip address or hostname in a ssh connection.
  • TRUELINE_USER_ALWAYS_SHOW_HOSTNAME=false: boolean variable that determineswhether to always show the ip address or hostname (not just in a ssh connection).
  • TRUELINE_USER_SHORTEN_HOSTNAME=false: boolean variable that determineswhether to display the full hostname (host.domain.com), or the shortened hostname(host).
• working_dir:
  • TRUELINE_WORKING_DIR_SPACE_BETWEEN_PATH_SEPARATOR=true: boolean variable thatdetermines whether to add (or not) a space before and after the path separator.
  • TRUELINE_WORKING_DIR_ABBREVIATE_PARENT_DIRS=false: boolean variable that whenset to true shows the full working directory (instead of trimming it). Each parentdirectory is shortened to TRUELINE_WORKING_DIR_ABBREVIATE_PARENT_DIRS_LENGTH.
  • TRUELINE_WORKING_DIR_ABBREVIATE_PARENT_DIRS_LENGTH=1: length of each parentdirectory when TRUELINE_WORKING_DIR_ABBREVIATE_PARENT_DIRS is enabled.

External

• TRUELINE_SHOW_VIMODE=false: boolean variable that determines whether or not to showthe current vi mode (if this is set to true and vi-mode is not already enabled thenTrueline will enabled it; vi-mode must be otherwise enabled separately in your.bashrc via set -o vi). When set to true a new segment is shown first (i.ebefore any other segment defined in TRUELINE_SEGMENTS) and it's appearance can becontrolled by means of the following variables:
  • TRUELINE_VIMODE_INS_COLORS_STYLE=('black' 'light_blue' 'bold'): insert modesegment foreground/background colors and font style.
  • TRUELINE_VIMODE_CMD_COLORS_STYLE=('black' 'green' 'bold'): command modesegment foreground/background colors and font style.
  • TRUELINE_VIMODE_INS_CURSOR='vert': insert mode cursor shape (possiblevalues are vert, block and under).
  • TRUELINE_VIMODE_CMD_CURSOR='block': command mode cursor shape (possiblevalues are vert, block and under).

Extensions

New segments can be easily added to the prompt by following this template:

_trueline_new_segment_name_segment() {
    local some_content=$(...)
    if [[ -n "$some_content" ]]; then
        local fg_color="$1"
        local bg_color="$2"
        local font_style="$3"
        local segment="$(_trueline_separator)"
        segment+="$(_trueline_content "$fg_color" "$bg_color" "$font_style" " $some_content ")"
        PS1+="$segment"
        _trueline_record_colors "$fg_color" "$bg_color" "$font_style"
    fi
}

and then simply including the new_segment_name in your TRUELINE_SEGMENTS array.

PRs with complicated segments are welcome!