Glitter: informative git prompt

glfmn 2019-10-03
This is a draft article; it is available for proofreading and testing.

Glitter is a cross-platform command-line tool and format language for making informative git prompts. Glitter's interpreter, glit will:

  • Read status information from your git repository through the git api
  • Parse and Interpret the provided format
  • Output your format with the requested information to stdout

Glitter is a binary tool which affords blazing speed, offers maximum flexibility, and painless installation. This makes Glitter an ideal alternative to alternative to tools like bash-git-prompt, zsh-git-prompt, and posh-git.

Glitter has been tested on Windows, Mac, and Ubuntu; it works in Powershell, zsh, bash, and theoretically any shell environment that supports a prompt command.

Installation

Go to the release page and download a binary for your platform.

To make sure Glitter is installed:

glit "'hello from git'" -e "'hello'"

It will output hello from git if the current directory is in a git repository and hello if it is not.

Build from source

If a download for you platform does not exist, install the rust toolchain, cmake and openssl first, and then:

cargo install glit

Setting up your shell

Once Glitter is installed, you need to set it to update your prompt.

Bash

Add the following snippet to your ~/.bashrc or just paste the snippet in your shell to try it without doing anything permanent.

# Format to use inside of git repositories or their sub-folders
export GIT_FMT="#g*(b)..#r(B)[+('↑')-('↓'), #~(#g(MARD):#r(maud)), h(#m('@'))]:#b*('\w')'\n\$ '"

# Format to use outside of git repositories
export PS1_FMT="#g(#*('\u')@'\h'):#b*('\w')'\$ '"

__set_prompt() {
    PS1="$(glit "$GIT_FMT" -b -e "$PS1_FMT")"
}

export PROMPT_COMMAND=__set_prompt
Powershell

Add the following snippet to your $PROFILE or just paste the snippet in your shell to try it without doing anything permanent.

# Format to use inside of git repositories
$GIT_FMT=":#y([#c*(b) #c(B):#~(+,-) | #~(#g(MARD):#r(maud):#m(h('@')))])"

function prompt {
    $path = $(get-location)
    glit "'$path'$GIT_FMT'> '" -e "'$path> '"
}
zsh

Add the following snippet to your ~/.zshrc file or just paste the snippet in your shell to try it without doing anything permanent.

# Format used in a git repository
export GIT_FMT="#g*(b)..#r(B)[+('↑')-('↓'), #~(#g(MARD):#r(maud)), h(#m('@'))] #b*('%~')"

# Fallback format used outside of git repositories
export PS1_FMT="#g*('%m')#b*('%~')"

precmd() { print -rP "$(glit "$GIT_FMT" -b -e "$PS1_FMT")" }
PROMPT="%# "
fish

Replace your ~/.config/fish/functions/fish_prompt.fish file with or just paste the snippet in your shell to try it without doing anything permanent.

function fish_prompt
    set -l path (prompt_pwd)
    # format used in git repositories
    set git "#g*(b)..#r(B)[+('↑')-('↓'), #~(#g(MARD):#r(maud)), h(#m('@'))] #y('$path')'\n> '"
    # fallback format used outside of git repositories
    set ps1 "#y('$path ')'> '"

    echo -e (glit $git -e $ps1)
end

Customizing your format

Glitter provides a flexible expression language which is easy to use and easy to prototype with.

`glit` is easy to experiment with.

Colorless Example
example-3
"b..B({+-}) [MARD] \(maud) h"
Compact Example
example-1
"[#c*(b)@#c(B):{+,-} \| #~(#g(MARD):#r(maud):h('@'))]"
Friendly for git Beginners
example-2
"#g*(b)..#r(B)[#g(+(#~('ahead '))), #r(-(#~('behind '))), #~(#g(MARD)#r(maud)), h('stash ')]"
Closely matches the information in git status -sb

A glitter format is made of 4 types of expressions:

  • Informational expressions
  • Group expressions
  • Strings
  • Separators
  • Format expressions

Git Information

Formatter Meaning Example
b branch name or head commit id master
B tracking branch with remote origin/master
+ # of commits ahead remote +1
- # of commits behind remote -1
m # of unstaged modified files M1
a # of untracked files ?1
d # of unstaged deleted files D1
u # of merge conflicts U1
M # of staged modified files M1
A # of added files A1
R # of renamed files R1
D # of staged deleted files D1
h # of stashed changes H1

You can provide other expressions as arguments to expressions which replace the default prefix which appears before the result or file count. For example, \h('@') will output @3 instead of H3 if your repository has 3 stashes. You can provide an arbitrary number of valid expressions as arguments to any of these expressions.

$ glit "b"
master
$ glit "b('on branch ')"
on branch master

Expressions generally only render any output if their corresponding values aren't empty; in other words, if there are no added files, glit will not produce A0 as the output of \A, but instead will output an empty string.

Grouping

Glitter will surround grouped expressions with parentheses or brackets, and will print nothing if the group is empty.

Macro Result
[] empty
\(a) (?1); note the preceeding \
<> empty
{} empty
{b} {master}
<+-> <+1-1>
[MAR] [M1A3] where R is 0
[r\(a)] empty, when r, a are 0
$ glit "b<M>"

Strings

Any characters between single quotes are strings. Strings appear untouched in the output; for example, 'exact' outputs exact.

$ glit "'hello world'"
hello world
$ glit "'\n\w\n\u'"
\n\w\n\u
$ glit "'separate' 'words'"
separate words

Separators

Separators appear between expressions to help differentiate or group them. Supported separators are:

Separator Symbol
Space
Bar/Pipe \|
At @
Underscore _
Colon :
Semicolon ;
Comma ,
Dot .

Any number of separators can be used between two expressions

$ glit "'hello', 'world'"
hello, world
$ glit "b@B::'git'"
master::git                 # there is no tracking branch (B)
master@origin/master::git   # there is a tracking branch (B)
$ glit "b[+] | B"
master[+1] | origin/master  # ahead 1 commit of tracking branch
master | origin/master      # no difference between master and tracking

Separators will always print if any expression in the group has printed before it, and if the expression immediately after prints anything.

glit "b [..B..]"            # [..B..] is a separate group
master [origin/master]      # nothing prints before or after B

This can lead to unexpected behavior like the following:

$ glit "b MA"
master M1A1                 # 1 staged change, 1 new file
masterA1                    # no staged changes, 1 new file

The solution is to group the expressions that follow somehow:

$ glit "b [MA]"
master [A1]
$ glit "b #~(MA)"           # tip: use reset style
master A1                   # notice no extra output

Formatting text

Glitter expressions support ANSI terminal formatting through the following styles:

Format Meaning
#~('...') reset
#_('...') underline
#i('...') italic text
#*('...') bold text
#r('...') red text
#g('...') green text
#b('...') blue text
#m('...') magenta/purple text
#y('...') yellow text
#w('...') white text
#k('...') bright black text
#[01,02,03]('...') 24 bit RGB text color
#R('...') red background
#G('...') green background
#B('...') blue background
#M('...') magenta/purple background
#Y('...') yellow background
#W('...') white background
#K('...') bright black background
#{01,02,03}('...') 24 bit RGB background color

Format styles can be combined in a single expression by just combining them:

Format Meaning
#wK('...') white text, black background
#r*('...') red bold text
#g_('...') green underline text
#~_*('...') underline bold text with the reset color
$ glit "#r*('hello world')"
$ glit "#g*(b)"
$ glit "#[255,175,52]('orange text')"
$ glit "#G('green background')"

glit can understand and respects complicated nested styles, providing maximum flexibility.

$ glit "#g('green text with some '#*('bold')' green text')"
$ glit "#g*(b(#~('on branch ')))"
Go back