Informative git prompt for zsh

A zsh prompt that displays information about the current git repository. In particular the branch name, difference with remote branch, number of files staged, changed, etc.

Further extended to asynchronize the git status process, so that the shell prompt is not blocked while parsing the git environment, with ideas derived from this stackoverflow question about asynchronous prompts..

Examples

The prompt may look like the following:

• (master↑3|✚1): on branch master, ahead of remote by 3 commits, 1 file changed but not staged
• (status|●2): on branch status, 2 files staged
• (master|✚7…): on branch master, 7 files changed, some files untracked
• (master|✖2✚3): on branch master, 2 conflicts, 3 files changed
• (experimental↓2↑3|✔): on branch experimental; your branch has diverged by 3 commits, remote by 2 commits; the repository is otherwise clean
• (:70c2952|✔): not on any branch; parent commit has hash 70c2952; the repository is otherwise clean

Here is how it could look like when you are ahead by 4 commits, behind by 5 commits, and have 1 staged files, 1 changed but unstaged file, and some untracked files, on branch dev:

Prompt Structure

By default, the general appearance of the prompt is:

(<branch><branch tracking>|<local status>)

The symbols are as follows:

Local Status Symbols

Symbol	Meaning
✔	repository clean
●n	there are n staged files
✖n	there are n unmerged files
✚n	there are n changed but unstaged files
…	there are some untracked files

Branch Tracking Symbols

Symbol	Meaning
↑n	ahead of remote by n commits
↓n	behind remote by n commits
↓m↑n	branches diverged, other by m commits, yours by n commits

Branch Symbol

When the branch name starts with a colon :, it means it’s actually a hash, not a branch (although it should be pretty clear, unless you name your branches like hashes :-)

Install

1. Clone this repository somewhere on your hard drive.

2. Source the file zshrc.sh from your ~/.zshrc config file, and configure your prompt. So, somewhere in ~/.zshrc, you should have:

   source path/to/zshrc.sh
   
   # Initialize the cached prompt environment
   init_async_git_super_status
   
   # An example prompt
   PROMPT='%B%m%~%b$(cached_git_super_status) %# '

3. Go in a git repository and test it!

4. As a cleanup step, add to your ~/.zlogout file, the following:

   rm -f "$PROMPTCACHE/prompt.$$" "$PROMPTCACHE/pid.$$".

   This will ensure that files in the $PROMPTCACHE don't accumulate forever.

Haskell (optional)

There is now a Haskell implementation as well, which can be four to six times faster than the Python one. The reason is not that Haskell is faster in itself (although it is), but that this implementation calls git only once. To install, do the following:

1. Make sure Haskell's stack is installed on your system
2. cd to this folder
3. Run stack setup to install the Haskell compiler, if it is not already there
4. Run stack build && stack install (don't worry, the executable is only “installed” in this folder, not on your system)
5. Define the variable GIT_PROMPT_EXECUTABLE="haskell" somewhere in your .zshrc

Customization

• You may change a number of variables (which name start with ZSH_THEME_GIT_PROMPT_) to change the appearance of the prompt. Take a look in the file zshrc.sh to see how the function git_super_status is defined, and what variables are available.
• You may define the variable $PROMPTCACHE, which defaults to ~/.prompts, as another directory where to store the prompt and pid cache files.

Enjoy!